The pro-regime militants consisted of a convoy of 20 vehicles that departed from the Nubl al Zahraa region and tried to advance into Afrin region.
A convoy of pro-Assad militants entering Syria's northwestern Afrin region turned back after Turkish artillery fire, President Recep Tayyip Erdogan said on Tuesday, adding the convoy was made up of "terrorists" acting independently.
Speaking at a joint news conference alongside his Macedonian counterpart Gjorge Ivanov in Ankara, Erdogan said "this file is closed for now."
Turkey launched "Operation Olive Branch" last month along with the Free Syrian Army (FSA) to rid Afrin of the YPG, the Syrian branch of the PKK. The PKK has been conducting a decades-long armed campaign against Turkey and has been designated a terrorist organisation by Ankara, the US and EU.
Erdogan said he had previously reached an agreement on the issue with Russian President Vladimir Putin and Iranian President Hassan Rouhani, and warned that the group, which he said backed the Syrian regime, would pay a heavy price.
"Unfortunately, these kind of terror organisations take wrong steps with the decisions they take. It is not possible for us to allow this. They will pay a heavy price," Erdogan told a news conference.
The pro-regime militia consisted of a convoy of 20 vehicles that departed from the Nubl al Zahraa region, at around 14:00 GMT and tried to advance into Afrin region.
The withdrawal of the pro-regime groups came when they were about 10 km away from Afrin.
A YPG official said at the weekend a deal had been struck for the Syrian army to enter Afrin and fight against the Turkish forces. On Monday morning, Syrian state media had said the pro-Assad militia would enter Afrin "within hours" - although the groups never materialised.