Duvar English/Reuters

Turkish and Syrian troops have engaged in most serious clashes in nearly nine years of war in Syria, with Idlib witnessing deaths from both countries.

Five Turkish soldiers were killed in a Syrian army attack on Feb. 10 as a meeting between Turkish officials and a visiting Russian delegation was ongoing, prompting Ankara to tell the delegation that “attacks on Turkish observation posts in Idlib must be stopped immediately and that such assaults will not remain unanswered.”

Earlier, Ankara said Russian-backed Syrian government forces had killed its Turkish soldiers in Idlib’s Taftanaz area, among thousands deployed there to help stem a Syrian offensive to retake the last rebel bastion in the country.

Funeral of a soldier killed in a Syrian army attack is seen on Feb 11.

In a statement following talks between Turkish Presidential spokesperson İbrahim Kalın and the Russian delegation, the presidency said the Russians were told that attacks on Turkish forces were unacceptable and that Moscow must fulfill its duties as mandated by a 2018 de-escalation deal between Ankara and Moscow.

The delegation, however, left Ankara with no apparent agreement on how to halt clashes that killed 13 Turkish soldiers in a week.

The Russians arrived in Ankara on Feb. 8, days after a Syrian government attack in Idlib killed eight Turkish soldiers. Ankara then hit Syrian targets in one of the most serious clashes between them in nearly nine years of war in Syria.

The Russian officials held talks at the foreign ministry on Feb. 8 and agreed to meet again on Feb. 10 after failing to reach a deal, Foreign Minister Mevlüt Çavuşoğlu said.

The rapid advance by Syrian government forces in Idlib, the last major enclave of insurgents opposed to President Bashar al-Assad, has driven nearly 700,000 people from their homes towards the closed-off Turkish border. Turkey, which already hosts 3.6 million Syrian refugees, says it cannot absorb any more.

Ankara has backed rebels looking to oust Assad, while Moscow and Tehran have supported Assad. Turkey has said it is ready for military action to halt Syrian advances. Moscow and Damascus say they are fighting terrorists in Idlib, which is largely controlled by jihadists.

President Recep Tayyip Erdoğan also chaired a security meeting with defense chiefs on Feb. 10 to discuss steps Turkey may take against the attacks on Turkish troops and the presidency said Turkey reaffirmed its determination to halt clashes and new migrant waves in Idlib.

Following the attack that killed five soldiers, Turkish forces have hit 115 Syrian government targets and destroyed 101 of them in retaliation, the Turkish Defense Ministry said.

The ministry said Turkish forces would continue to retaliate any attacks on its troops, which have observation posts in the far northwest of Syria.

“Up to now, 115 [Syrian] regime targets were immediately fired upon, and 101 regime elements were neutralized according to initial information from various sources,” the ministry said in a statement.

“It was found that three tanks and two mortar positions were destroyed, while one helicopter was also hit.”

The incidents are among the most serious confrontations between Turkish and Syrian troops in nearly nine years of conflict in Syria and Turkey has said it will drive back Syrian forces if they do not pull back by the end of this month.

“Their attacks against our posts have made an operation necessary,” Ömer Çelik, spokesman for President Recep Tayyip Erdoğan’s ruling Justice and Development Party (AKP), told reporters in Ankara.

Turkey has poured 5,000 troops and convoys of military vehicles across the border, carrying tanks, armored personnel carriers and radar equipment to bolster its existing military positions.

A Turkey-backed Syrian rebel commander said the insurgents had also launched a military operation near the town of Saraqeb, south of Taftanaz, with Turkish artillery support.

A condolence message, meanwhile, was shared from the Twitter account of the U.S. embassy in Ankara.

“We send our condolences to the friends and families of the five Turkish soldiers killed today and speedy recovery to those wounded. We stand by our NATO Ally Turkey and will continue to oppose normalization of the Assad regime into the international community,” the message shared on Feb. 10 read.