"It is an extremely worrying escalation in the conflict that the Turkish troops and the Syrian army are now bombing each other in the restive northwest region," Guterres said.

"My strong appeal is for a cessation of hostilities. We do not believe there is a military solution for the conflict in Syria. We have said repeatedly that the solution is political," he added

5 Turkish soldiers and 3 civilians were killed and 9 injured, including 1 in critical condition when Syrian regime artillery fire targeted Turkish surveillance point in Idlib province of northern Syria.

Retaliatory fire from Turkey army killed at least 13 Syrian government soldiers, the local sources reported. (ILKHA)