Turkey deploys more tanks to its border with Syria
Close to where Syrian government forces, backed by Russia, are continuing their advance on the last rebel stronghold in the northwestern Idlib province.
Weathering Turkish artillery barrages on Thursday (February 6) as they tried to seize the town of Saraqeb.
On Monday (February 3), shelling by Syrian forces killed eight Turkish personnel, who then retaliated with their own deadly strikes - an escalation that shook the fragile cooperation between Ankara and Moscow, which back opposing sides in the war.
Turkey's foreign minister is warning Russia that it must stem the Syrian government attacks immediately.
Adding that Ankara is determined to stop what it calls a "human drama" unfolding in Idlib.
President Bashar al-Assad's swift military advance there has also caused yet another exodus of civilians towards the Turkish border.
Russia meanwhile said militants in Turkey's 'zone of responsibility' were attacking Syrian government forces and the Russian military, confirming some of its troops were killed.
Syrian forces backed by air strikes have encircled and entered Saraqeb, witnesses and observers say.
It lies at the junction of two main roads that Assad wants to bring under his control.
Fighting in Idlib has accelerated despite several ceasefire attempts, the latest in January.