Turkish bombing raids killed 10 fighters loyal to the Syrian government on Wednesday at a checkpoint they were manning near the Kurdish enclave of Afrin, a monitor said.
"The air strikes targeted a checkpoint on the only road leading from Afrin to regime-controlled territory to the southeast," the Britain-based Syrian Observatory for Human Rights said.
Of the 10 fighters killed, eight were from the nearby regime-held town of Nubul, the Observatory said.
Ankara and allied Syrian rebels have waged an offensive against the Kurdish People's Protection Units (YPG), who control the Afrin enclave, since January 20.
The enclave is bordered to the north and west by Turkey but also lies adjacent to government-controlled Syrian territory.
Pro-Turkish forces have seized several border areas and have almost fully encircled the city of Afrin.
The road that was bombed on Wednesday is the only official way out of the town, and while it has not been fully captured by pro-Turkish assault, it is within firing range.
Observatory head Rami Abdel Rahman said some civilians were trying to escape from Afrin along smuggling routes avoiding the main road.
Around 350,000 people live in the city, including families displaced from other parts of the enclave.
Turkey has killed dozens of pro-Damascus fighters backing the YPG in Afrin.