At the same time, clashes between the Syrian army and Turkish forces have moved the two countries closer to an all-out conflict than at any other point in the nine-year-old civil war.

Turkey’s Recep Tayyip Erdoğan, said that Damascus would pay a “heavy price” for any future attacks on Turkish troops, after the deaths of 13 Turkish military personnel in the area in the past week.

The two sides have traded artillery fire since Ankara sent reinforcements to Turkish observation posts in Idlib to secure its border and stem the bloodshed caused by the regime assault, which is being carried out with the help of Russian airpower.

As well as two deadly attacks on Turkish positions, dozens of Syrian government troops and allied militiamen have been killed in the escalation, according to the Syrian Observatory for Human Rights, a war monitor. The Turkish defence ministry said it had “neutralised” 101 Syrian regime troops, without giving evidence.