President Recep Tayyip Erdogan says the offensive is aimed at removing Kurdish-led forces from the border area and creating a "safe zone" so millions of Syrian refugees can be returned.
The move came after the United States announced it was withdrawing its troops from the region, leaving the Syrian Democratic Forces (SDF), its main ally in the battle against the Islamic State of Iraq and the Levant (ISIL or ISIS) armed group, without US military support.
Heavy clashes between Turkish forces and the SDF are under way in the Syrian border towns.
The SDF, led by the Kurdish People's Protection Units (YPG), has appealed to the US and its allies for a "no-fly zone" to protect it from Turkish air attacks. Turkey considers the YPG a "terrorist" group.
Here are the latest updates:
Thursday, October 10
NATO chief calls for 'restraint'
NATO Secretary-General Jens Stoltenberg urged Turkey to show "restraint" as the country continued its offensive.
In a news conference in Athens, Stoltenberg called on Turkey to ensure its actions in the region were "measured and proportionate."
Speaking alongside Stoltenberg, Greece's Prime Minister Kyriakos Mitsotakis said the offensive would add difficulty in finding a political solution to end Syria's long civil war.
Russia accuses US of 'demographic engineering' in Syria
Turkey's operation was a result of "demographic engineering" that was carried out by member-countries of the US-led international coalition in Syria, Russian Permanent Representative to the UN Vassily Nebenzya said at the international body's headquarters in New York.
Nebenzya told reporters at the international body's New York headquarters that the coalition was "reaping the fruit" of their demographic policies.
"We are encouraging the Kurds to engage in dialogue with the Syrian government, but as you know they preferred other protectors," he added.
Turkish offensive 'will not exceed 30km'
Turkey's Foreign Minister Mevlut Cavusoglu said his country's operation would not go further than 30km (20 miles) deep into Syria.
"When we go 30km deep in the safe zone, terror there will be removed," he told CNN Turk, referring to the presence of Kurdish fighters considered by Ankara as "terrorists",
Cavusoglu also said Turkey had the right to use the air space over Syria as part of its campaign and that the "air space does not belong to the United States".
Turkey claims 174 'terrorists' killed in offensive
Turkey's Defence Ministry said 174 "terrorists" were "neutralised" in its cross-border military offensive.
The ministry tweeted that the number included 19 alleged fighters killed in an air raid on a shelter used by the YPG group in Ras al-Ain.
US condemns Turkey at UNSC
Kelly Craft, the US ambassador to the United Nations, condemned Turkey's offensive at an emergency meeting of the UN Security Council.
"The US has not in any way endorsed the decision of the government of Turkey to mount a military incursion into northeast Syria," Craft told reporters.
She added that failure to "play by the rules" and to guarantee that ISIL does not exploit these actions "will have consequences".
Syria rejects dialogue with US-backed Kurdish forces
Syria's Deputy Foreign minister Faisal Maqdad said US-backed Kurdish-led forces had betrayed their country and accused them of a separatist agenda that gave Turkey a pretext to violate his country's sovereignty.
"We won't accept any dialogue or talk with those who had become hostages to foreign forces ...There won't be any foothold for the agents of Washington on Syrian territory," Maqdad told reporters in his office in Damascus.
UN chief Guterres calls for de-escalation of conflict in Syria
United Nations Secretary-General Antonio Guterres called for a de-escalation of the conflict in Syria.
"I want to express my deepest concerns about the escalation of conflict in eastern Syria. It is absolutely essential to de-escalate," he said in Copenhagen.
Norway suspends arms exports to Turkey
Norway announced that it was suspending all new arms exports to Turkey amid the ongoing offensive.
"Given that the situation is complex and changing quickly, the foreign ministry as a precautionary measure will not handle any new demands for exports of defence material or material for multiple uses... to Turkey," Norwegian Foreign Minister Ine Eriksen Soreide said in an email sent to AFP.
Soreide added that the foreign ministry would also review all licences for arms exportation that have already been issued.
Turkish bombardment continues
Al Jazeera's Charles Stratford, reporting from Akcakale, said the bombardment of towns near the Turkish-Syrian border continued throughout the day.
He added that things were "relatively quiet" early in the evening, even as sporadic artillery shelling could be heard "targeting positions in the town of Tal Abyad" and the bombardment was likely to continue.
Aid agencies warn of humanitarian crisis
Fourteen aid agencies called for "urgent action" to prevent further deterioration of the humanitarian situation in northern Syria.
In a joint statement, they said an estimated 450,000 people, including 90,000 internally displaced people, live within 5km (3 miles) of the Syria-Turkey border and are at risk "if all sides do not exercise maximum restraint and prioritise the protection of civilians".
The organisations described the security situation in the area as fragile, pointing to the "tens of thousands of fighters and their families being held in camps and detention centres".
"All children must be protected and provided humanitarian assistance, and countries of origin must take immediate steps to repatriate the estimated 9,000 children from at least 40 different nationalities who are in north-east Syria."
Six killed in Turkish border towns in mortar fire from Syria: governor's offices
At least six people, including a nine-month-old baby, were killed during mortar and rocket fire from Syria into Turkish border towns, governors' offices of southeastern Turkish provinces said.
Three people were killed and 45 people wounded as shells hit the border towns of Akcakale and Ceylanpinar, the Sanliurfa governor's office said in a statement.
The terrorist organization PKK/PYD-YPG committed yet another heinous crime against humanity today. They killed two civilians, including a baby, in a mortar attack against Akçakale, a Turkish town at the Syrian border.#MSB #TSK #OperationPeaceSpring— T.C. Millî Savunma Bakanlığı (@tcsavunma) October 10, 2019
The Turkish army detected and destroyed PKK and YPG fighters targeting Turkish civilians, the defence ministry said, following the shelling attack.
Separately, three people were killed and more than 20 people wounded as shells hit the border town of Nusaybin, Mardin governor's office said.
Nine dead in Turkish operation: SDF
SDF said Turkish air raids and shelling had killed nine civilians in northeast Syria since the start of Ankara's offensive.
SDF repeats call for no-fly zone
An SDF official repeated a call to impose a no-fly zone amid the ongoing Turkish offensive.
"We ask for no-fly zone over our area. At least we will not have civilian casualties then," Sinam Mohamad, the US co-chair of the Syrian Democratic Council, the SDF's political arm, told reporters.
Turkish lira down amid Syria offensive
The lira weakened slightly against the dollar as investors tried to come to grips with whether the Turkish offensive in Syria will lead to the United States slapping punishing economic sanctions on Ankara.
On Wednesday, US President Donald Trump said he would devastate Turkey's economy if its operation in northeast Syria wiped out the Kurdish population there.
Read more here.
Italy summons Turkish envoy
The Italian foreign ministry summoned Turkey's ambassador to protest against Ankara's offensive in Syria.
The ministry called for an end to unilateral actions and recalled that the only lasting solution to the crisis in Syria was a UN-mediated peace process.
Italian Foreign Minister Luigi Di Maio said earlier that Turkey's offensive was "unacceptable" and called for an immediate end to the fighting.
Kurdish shelling kills 4 civilians on Turkish towns: State TV
The death toll from the shelling of Turkish border towns rose to four on Thursday, Turkey's state media reported.
Two civilians were killed in Mardin province, TRT said, adding to the two deaths reported in neighbouring Sanliurfa province, where a municipal worker and a nine-month-old baby were reported dead.
Turkish politicians, public voice support for Syria military push
The Turkish public and political elite have largely thrown their support behind the country's forces fighting in northern Syria, standing in defiance against voices in the international community condemning Ankara's operation.
The offensive was widely praised on the front pages of Turkish newspapers on Thursday, with TV stations showing soldiers heading for the border being cheered by flag-waving crowds.
Read more here.
Turkish offensive risks helping ISIL: Macron
French President Emmanuel Macron said Ankara's operation ran "the risk of helping Daesh [Islamic State] rebuild a caliphate".
"I call on Turkey to put an end to it as soon as possible," he told journalists at a press conference in Lyon.
Trump calls for 'end to endless wars'
US President Donald Trump defended his decision to pull out US troops from northern Syria and said he was trying to end "endless wars".
In a Twitter post, Trump criticised those who wanted to send "thousands of [US] soldiers" and start a "new war all over again".
Turkey has been planning to attack the Kurds for a long time. They have been fighting forever. We have no soldiers or Military anywhere near the attack area. I am trying to end the ENDLESS WARS. Talking to both sides. Some want us to send tens of thousands of soldiers to....— Donald J. Trump (@realDonaldTrump) October 10, 2019
Al Jazeera's Kimberly Halkett, reporting from Washington, DC, said Trump was "defending his 2016 campaign promise", noting that the US president was now supporting sanctions against Turkey, after "dragging his heels" on the issue.
Israel condemns Turkish operation
Israel criticised Turkey's "invasion" of Kurdish-controlled areas in northern Syria and warned against the "ethnic cleansing" of the Kurdish people, Prime Minister Benjamin Netanyahu said, in a statement posted on Twitter.
The Israeli prime minister said he was "prepared to extend humanitarian assistance to the gallant Kurdish people".
France summons Turkish ambassador over Syria offensive
France's foreign ministry summoned the Turkish ambassador to Paris, Ismail Hakki Musa, over Ankara's air and ground offensive into Kurdish-controlled areas of northern Syria, a diplomatic source said.
"The ambassador in France was summoned in the early afternoon," the source said, on the second day of the Turkish operation against Syrian Kurdish forces.
Erdogan threatens to send Syrian refugees to Europe
The Turkish president said Ankara will send the 3.6 million Syrian refugees in Turkey to Europe if European countries label the country's military operation in Syria as an occupation.
"We will open the gates and send 3.6 million refugees your way," Erdogan said in speech to his AK Party.
Speaking from Istanbul, Al Jazeera's Sinem Koseoglu said the speech targeted an international audience.
"Since the operation started, it seems Ankara is not happy about what the international public opinion has been, because the rhetoric in media is thought to be against Turkey," she said.
"Erdogan wanted to clear the grey areas for the international public opinion because many media outlets have been saying Turkey is about to invade or plans to invade Syria," she continued. "Today Erdogan made it clear that this is not an invasion, and the operation is to clear the area from what Ankara calls terrorist groups."
Erdogan defends Syria operation after wave of criticism
The Turkish president defended Turkey's incursion into Syria after a wave of international criticism, saying the military operation would support Syria's territorial integrity by confronting Kurdish control of the country's northeast.
"They are not honest, they just make up words," Erdogan said of Turkey's critics, singling out Saudi Arabia and Egypt. "We, however, create action and that is our difference," he told members of his AK Party in Ankara.
Erdogan said 109 "terrorists" had been killed since Ankara launched an offensive into Syria the previous day.
Russia will push for Turkey-Syria 'dialogue' on Kurds: Lavrov
Russian Foreign Minister Sergey Lavrov said Ankara and Damascus should discuss the issue of Kurdish forces in northeastern Syria directly, calling Turkey's cross-border assault a product of US policies.
"We will strive for the necessity of dialogue between Turkey and Syria," he said.
Turkey has "legitimate concerns about the safety of its borders" but had not been able to properly raise them with Damascus as this was "made difficult by the actions of the Americans and the coalition" east of the Euphrates river, he said.
Iran calls for 'immediate halt' to Turkish Syria offensive
Iran called for an immediate halt to Turkey's offensive on Kurdish-ruled northeastern Syria, citing concern for the dangers to civilians in the conflict zone.
"Iran... emphasises (the need for) an immediate halt to the assault and the departure of Turkish military units from Syrian territory," the foreign ministry said in a statement.
Iran is a close ally of the Syrian government, which has sought to exploit the Turkish offensive against Kurdish forces that were the mainstay of the US-led campaign against ISIL in Syria to win the region back to central government control.
Italian FM: Turkish operation in Syria is "unacceptable"
Turkey's offensive against Kurdish forces in Syria is "unacceptable", Italian Foreign Minister Luigi Di Maio said on Thursday, calling for an immediate end to the fighting.
"As a government we think that the Turkish offensive initiative is unacceptable. We condemn it ... because military action in the past has always led to more terrorism," Di Maio, who is head of the co-ruling Five Star Movement, said on the sidelines of a conference in Rome.
"We call for an immediate end to this offensive which is absolutely not acceptable given that the use of force continues to endanger the life of the Syrian people, who have already experienced tragedy in recent years," he said.
Turkey-backed Syrian rebels heading to fight SDF: Spokesman
Turkey-backed Syrian rebel fighters are on their way to battle fronts in northeastern Syria in support of Turkish troops who have crossed the countries' border, a spokesman for the rebels said on Thursday.
Kurdish-led SDF forces have "dug in" the area, Major Youssef Hamoud said.
The fighters of the Syrian opposition National Army are moving towards the two main towns in the area, Tal Abyad and Ras al-Ain, he said.
Heavy clashes under way in border villages: SDF
Heavy clashes are under way in Syrian border villages between advancing Turkish forces and Syrian Democratic Forces (SDF) soldiers, an official in the Kurdish-led SDF said on Thursday.
"Fierce clashes are continuing in the villages that (Turkish forces) are trying to enter," said Marvan Qamishlo, an SDF media official.
Turkey targeted prison holding ISIL fighters: Syrian-Kurdish authorities
The Kurdish-led administration in northern Syria accused Turkey of shelling a prison holding ISIL fighters of more than 60 nationalities, calling this "a clear attempt" to help them escape.
There was no immediate comment from Turkey.
The shelling on Wednesday night targeted part of Chirkin prison in the city of Qamishli, the Kurdish-led authorities said in a statement.
SDF says it stopped advancing Turkish military
A Kurdish-led group and Syrian activists claimed that despite the heavy barrage, Turkish troops had not made much progress on several fronts they had opened over the past hours.
But their claims could not be independently verified and the situation on the ground was difficult to assess.
Mustafa Bali, a spokesman for the Kurdish-led Syrian Democratic Forces, said their fighters had repelled Turkish forces' ground attacks.
Turkey using 'air power' to advance through border
Al Jazeera's Zeina Khodr said the Turkish military was using air raids as well as artillery bombardment to target the defences of the Kurdish-led Syrian Democratic Forces (SDF), mainly along the border.
"We still don't know how much of an advance Turkish soldiers and their local allies - the opposition [Free Syrian Army] - have made, but according to officials and defence ministry sources, the operation is moving ahead smoothly," Khodr said, speaking from the Turkish border town of Akcakale.
The SDF, Khodr explained, are out-numbered and out-gunned, and the flat terrain will make it easy for the Turkish army to advance. The first phase of the operation is concentrated on the 100-kilometre stretch of territory between two Syrian border towns: Tal Abyad and Ras al-Ain.
Turkey's Defence Ministry shared a brief video of its commandos in action, and said Turkish jets and artillery had struck 181 targets east of the Euphrates river in Syria since the operation began.
Within the scope of the Operation Peace Spring; Turkish Armed Forces hit 181 terrorist positions with air forces elements and fire supporter vehicles#OperationPeaceSpring— Peace Spring Operation (@peacespringOP) October 9, 2019
No go-ahead on Turkish operation: Pompeo
US Secretary of State Mike Pompeo said Washington did not give Ankara "a green light" for a military offensive into Syria.
"That's just false," he said in an interview with PBS channel, but did not elaborate other than to say that Turkey has a "legitimate security concern".
"They have a terrorist threat to their south," Pompeo said. "We've been working to make sure that we did what we could do to prevent that terror threat from striking the people in Turkey while trying to achieve what is in America's best interest: the threat from radical Islamic terrorism emanating from Syria."
Pompeo said the US was leaving Syria because it had achieved its goal of eliminating ISIL's control of the territory, which the SDF had played an instrumental part in.
"We'll continue to be in a position to do what we need to do to keep the American people as safe as we possibly can from this threat," he said.
Turkish lira steady after launch of Syria offensive
The Turkish lira was steady against the dollar early on Thursday after Turkish troops and their Syrian rebel allies launched a ground operation against a Kurdish militia in northeast Syria overnight.
The lira was little changed at 04:21 GMT compared with a day earlier when it closed at 5.8679. It had weakened 0.5 percent on Wednesday when the operation began with air raids.
US airmen denounces 'abandoning fierce allies'
US Air Force Major Jason Baker - who flew combat missions and provided support to Kurdish-led ground forces in the fight against ISIL in 2016 - wrote in an opinion piece in USA Today that the SDF was crucial in defeating the armed group in northern Syria.
"The Kurds have proved time and again their capability as a disciplined, effective fighting force and their commitment to the kind of stable, moderate governance that is sorely lacking in the region … The [US] administration's plan of abandoning them now would not just be a reversal of long-established policy, it also would be a betrayal of one of America's few reliable regional partners."
Australia worried about Turkish operation, ISIL resurgence
Australian Prime Minister Scott Morrison said on Thursday he had been in contact with the Turkish and US governments overnight, but admitted to being worried about the situation in Syria following Ankara's announcement of a military operation.
"We are very concerned about what this could potentially mean for the Kurdish people," he said.
"We're concerned about what this could mean for the potential for the resurgence of Daesh," he added, using the Arabic acronym for ISIL.
Read more updates here
SOURCE: Al Jazeera and news agencies