Turkey, which supports several rebel groups in the area, immediately responded to the attack by hitting Syrian "regime targets", the ministry said on Twitter.

The latest casualties have brought the number of Turkish security personnel killed in regime fire in Idlib this month to 19.

Damascus backed by Russian air strikes has pressed an offensive to take back the last rebel bastion of Idlib.

Hundreds of thousands of people have been forced to flee their homes since December in the largest displacement since the civil war in Syria broke out almost nine years ago.

The attacks on Turkish forces have caused strains between the regime's key ally Russia and Turkey.

Ankara urged the regime to pull back by the end of February from behind its military posts in Idlib.

Russian diplomats and military officials were due to hold second round of negotiations with their Turkish counterparts on Thursday.