More than two dozen Turkish soldiers have been killed in an air strike by Syrian government forces in north-east Syria, a Turkish official said.
The deaths mark a serious escalation in the conflict between Turkish troops and Russia-backed Syrian forces that has been waged since early February.
Rahmi Dogan, the governor of Turkey’s Hatay province bordering Syria’s Idlib region, said 29 soldiers were killed and others were seriously wounded in the attack late on Thursday.
In addition to three Turkish soldiers killed in Idlib earlier, the casualties mark the largest death toll for Turkey in a single day since Ankara first intervened in Syria in 2016.
At least 43 have been killed in Idlib since the start of February.
Turkish President Recep Tayyip Erdogan was holding an emergency security meeting in Ankara, the state-run Anadolu news agency reported.
Turkish foreign minister Mevult Cavusoglu spoke to Nato Secretary General Jens Stoltenberg by telephone.
The air strike came after a Russian delegation spent two days in Ankara for talks with Turkish officials on the situation in Idlib, where a Syrian government offensive has sent hundreds of thousands of civilians fleeing towards the Turkish border.
The offensive has also engulfed many of the 12 military observation posts Turkey has in Idlib.
The air strike came after Turkey-backed Syrian opposition fighters retook a strategic north-western town from government forces on Thursday, opposition activists said, cutting a key highway just days after the government reopened it for the first time since 2012.
Despite losing the town of Saraqeb, Syrian President Bashar Assad’s forces made major gains to the south.
Assad now controls almost the entire southern part of Idlib province after capturing more than 20 villages on Thursday, state media and opposition activists said. It is part of a weeks-long campaign backed by Russian air power into Syria’s last rebel stronghold.
Violence in Idlib province also left three more Turkish soldiers dead, according to Mr Erdogan, raising the number of Turkish troops killed in Syria this month to 21.
Thousands of Turkish soldiers are deployed inside rebel-controlled areas of Idlib province, which is dominated by al-Qaida-linked militants.
Turkey’s UN ambassador Feridun Sinirlioglu told the Security Council on Thursday that Turkey was committed to upholding a fragile ceasefire agreement that Turkey and Russia reached on Idlib in 2018.
The Syrian government troops’ “deliberate attacks on our forces has been a turning point. We are now determined more than ever to preserve Idlib’s de-escalation status”, he said.
Syria’s Defence Ministry said insurgents were using Turkey-supplied portable surface-to-air missiles to attack Syrian and Russian aircraft. Earlier this month, Turkish-backed opposition fighters shot down two helicopter gunships belonging to the Syrian military.
The Britain-based Syrian Observatory for Human Rights, an opposition war monitoring group, said opposition fighters seized the town of Saraqeb after intense bombardment by Turkish troops.
Turkey and Russia support opposite sides in Syria’s brutal civil war, with Ankara backing the opposition and Moscow backing Assad.
Saraqeb’s loss is a big setback for Assad. It sits on the strategic M5 highway linking the northern city of Aleppo with the capital, Damascus.
Syrian troops recaptured the last rebel-controlled section of the M5 earlier this month. Officials had hailed the reopening of the motorway as a major victory in the nine-year conflict.
The Syrian government’s military campaign to recapture Idlib province has triggered a humanitarian catastrophe and the war’s largest single wave of displacement.
According to the United Nations, almost 950,000 civilians have been displaced since early December, and more than 300 have been killed. Most have fled farther north to safer areas near the Turkish border, overwhelming camps already crowded with refugees in cold winter weather.