At least 33 Turkish soldiers have been killed in an air strike by Syrian “regime forces” in north-western Syria, a senior Turkish official has said.
More were hurt in Idlib province, said Rahmi Dogan, the governor of Turkey’s Hatay province. Other reports put the death toll higher.
Turkey later retaliated against Syrian government targets.
Syrian forces supported by Russia are trying to retake Idlib from rebels who are backed by Turkish soldiers.
The Syrian authorities have so far made no public comments on the latest escalation in Idlib, the last Syrian province to remain in opposition hands.
What’s the latest?
The Turkish military began hitting back at Syrian targets after President Recep Tayyip Erdogan held an urgent top-level security meeting in Ankara late on Thursday.
Defence Minister Hulusi Akar and senior Turkish military commanders immediately went to the Syrian border to direct a wave of ground and air attacks against Syrian President Bashar al-Assad’s forces.
President Erdogan wants the Syrian government forces to pull back from positions where Turkey has set up military observation posts and earlier threatened to attack them if they did not halt their advance.
But Syria’s government and Russia have rejected his demand to pull back to ceasefire lines agreed in 2018. Russia has also accused Turkey of violating the 2018 ceasefire by backing rebels with artillery fire.
The UK-based monitor, the Syrian Observatory for Human Rights, said at least 34 Turkish troops had been killed in Thursday evening’s air strike.
The wounded had been brought back to Turkey for treatment, Mr Dogan said.
“All known” Syrian government targets were under fire by Turkish air and land support units, Turkey’s communications director Fahrettin Altun was quoted by state news agency Anadolu as saying. Turkey had decided to “respond in kind” to the attack, Mr Altun said.
What has the reaction been?
Nato Secretary General Jens Stoltenberg spoke by phone to Foreign Minister Mevlut Cavusoglu of Turkey, a key member of the military alliance.
Mr Stoltenberg “condemned the continued indiscriminate air strikes by the Syrian regime and its backer Russia in Idlib province”, his spokesperson was quoted as saying by AFP news agency.
A spokesman for the US state department said in a statement: “We stand by our Nato ally Turkey and continue to call for an immediate end to this despicable offensive by the Assad regime, Russia and Iranian-backed forces.
“We are looking at options on how we can best support Turkey in this crisis.”
Meanwhile, UN Secretary General António Guterres expressed “grave concern” over the latest escalation, calling for an immediate ceasefire.
Will Ankara or Damascus back down?
The scene is set for a full-scale confrontation between Turkey and Syria.
This leaves all sorts of questions.
Will Ankara or Damascus back down? Can Moscow – hardly a neutral party – in some way encourage de-escalation?
And is there any way to persuade the Syrian regime to halt its wider offensive in Idlib?
This appears doubtful since Syrian President Bashar al-Assad seems intent on taking back control of the area, and the Russians have already been backing him to this end.
And what of the human tragedy that is unfolding?
Turkey has already taken in some 3.7 million refugees.
This now is becoming a controversial issue in Turkish domestic politics, and Turkey’s exasperation may lead it to send a wave of refugees towards Europe.
The latest clashes came after the Turkey-backed rebels said they had retaken the strategic town of Saraqeb from Syrian government forces on Thursday.
The fighting in Idlib has driven nearly a million Syrians from their homes since December. The UN said a full-scale battle there could result in a “bloodbath”.
Reuters news agency quoted a senior Turkish official on Thursday as saying that Turkey had decided to stand down its border guards and no longer prevent Syrian refugees from trying to reach Europe. However, this has not been officially confirmed.
Earlier on Thursday, Mr Erdogan said three Turkish soldiers had been killed in an air strike in Idlib.
Turkey’s defence ministry said it had responded to that incident by hitting Syrian “regime targets”.
Russia has rejected calls in the UN Security Council for a humanitarian ceasefire in northern Syria.
Responding to a statement from Belgium and Germany that the killing of civilians must stop, the Russian ambassador said the only solution was to chase what he called the terrorists from the country.