0737 GMT September 18, 2019
The terrorists pulled back from the town of Khan Sheikun and the countryside to its south overnight and in the early hours of Tuesday, the Syrian Observatory for Human Rights said.
The withdrawal means an important Turkish observation point in the nearby town of Morek is effectively surrounded by government forces, observatory chief Rami Abdel Rahman told AFP.
On Monday, a Turkish military convoy crossed the border into the Idlib region, sparking condemnation from Damascus as Ankara alleged airstrikes had targeted its troops.
The convoy halted just north of Khan Sheikhun on Monday afternoon and remained there on Tuesday, after government forces took control of a section of the highway into the town.
Pro-government newspaper Al-Watan said Monday morning's strike targeted a terrorist vehicle scouting the road in front of the Turkish convoy.
"The Syrian Army in its own way sent a clear message to the Turkish regime by forcing convoys sent by Ankara to help the terrorists in Khan Sheikhun to come to a halt," it said.
It was a "clear warning against any Turkish attempt to resuscitate the terrorists," the paper said, adding that the strike had "Russian support".
After eight years of war, the Idlib region on the border with Turkey is the last major stronghold of terrorists fighting President Bashar al-Assad's government.
Since January, it has been administered by the Hayat Tahrir al-Sham alliance, which is led by terrorists from Syria's former Al-Qaeda affiliate.
The region of some three million people was supposed to be protected by a Turkish-Russian buffer zone deal signed last year.
But government and Russian forces launched an offensive in late April to flush terrorists out of it.
The war in Syria has killed more than 370,000 people since the terrorists first took arms after anti-government protests erupted in 2011.
Rival interventions by outside powers have turned it into a complex conflict with multiple battle fronts that has driven millions of civilians from their homes.