Syrian government forces battled rebels and weathered Turkish artillery barrages on Thursday as they tried to seize Saraqeb town in northwestern Idlib province in a new push to recapture the last rebel stronghold, witnesses and a war monitor said.
President Bashar al-Assad's swift military advance through Idlib province, backed by Russian air strikes, has caused an exodus of civilians towards Turkey's border in the past two weeks, risking a military confrontation with Turkey, whose leader has threatened to drive back the Syrian forces.
Turkish Foreign Minister Mevlut Cavusoglu said on Thursday that Ankara expected Russia to immediately stop the government attacks, which killed eight Turkish military personnel on Monday and prompted Turkish forces to strike back.
"We conveyed our determination to our Russian counterparts," he said, adding that Ankara was determined to stem the "humanitarian drama" in Idlib which Turkey says has displaced nearly 1 million people.
Syrian forces backed by air strikes had on Wednesday encircled and entered Saraqeb, 15 km (9 miles) east of Idlib city, the British-based Syrian Observatory for Human Rights had said in a report corroborated by witnesses.
The town lies at the junction of two main roads that Assad seeks to fully control under the campaign to regain Idlib province, the last rebel bastion in the nearly nine-year-long civil war.
Rebel fighters "managed to push back government forces from most of Saraqeb in an attack from the northern part of the town that coincided with Turkish shelling against advancing government forces," the Observatory said.
Witnesses said government forces came under shelling from Turkish observation posts in the area.
The fighting, taking place despite a Jan. 12 ceasefire deal between Turkey and Russia, disrupted a fragile cooperation between the two countries that back opposing sides in the conflict, raising concerns over future collaboration.
The Kremlin said on Thursday that militants in Turkey's "zone of responsibility" in Idlib province were continuing to attack Syrian government forces and Russian military infrastructure.
Kremlin spokesman Dmitry Peskov said there were no plans currently for President Vladimir Putin and Turkish President Tayyip Erdogan to meet to reduce tensions in Idlib but that such a meeting could be quickly organised if needed.
Russia also said some of its troops had been killed in the militant attacks - its first confirmation of casualties in the current round of fighting.
The battle for Idlib marks a crucial stage of a war that has killed hundreds of thousands of combatants and civilians, made millions refugees in their own country or overseas, and fractured the wider Middle East since it broke out amid the Arab Spring in 2011.
The forces arrayed against Assad, Syria's ruler for nearly 20 years, have failed to dislodge him but he now presides over a devastated country.
The escalation in Idlib also comes at a time of heightened tension between the United States and Iran, Assad's other main military ally, after the killing last month in a U.S. strike of an Iranian general who was the architect of Tehran's military operations in the region and an important figure in Syria's war.
Russian and Iranian support has helped Assad win back nearly all the territory lost to rebels. The threat of direct confrontation between arch-enemies Israel and Iran has also long simmered in Syria, where the Iranian military has built a presence early in the civil war.
Early on Thursday, Syrian air defences intercepted Israeli missiles over Damascus that were fired at military targets in southern Syria including near the capital, the Syrian defence ministry said.
The attacks by Israeli warplanes were launched in two waves, one near Damascus and another near Deraa and Quneitra provinces, it said.
The Syrian air defences downed a large number of missiles but the attacks had caused material damage and injured eight "fighters", it said, without specifying their nationality.
The Israeli military declined to comment.
Israel has repeatedly bombed Iranian-backed militia targets in Syria, saying its goal was to end Tehran's military presence there.