Members of the Free Syrian Army also seized large quantities of ammunition from the army unit that was attacked near the village of Bedama near the border with Turkey.
“Troops are bombing and helicopters flying overhead. Fighting has been going on since midday (Thursday) between regime forces and (army) deserters in Aazaz, opposition activist Mohammed Halabi in Aleppo province told AFP by telephone.
The Syrian Observatory for Human Rights said at least three soldiers and a rebel were killed in the confrontation.
The city of Aazaz is strategically positioned on the road to safety in neighboring Turkey for wounded and fleeing civilians as well as a supply route for Free Syrian Army rebels.
On Thursday, a bus, with women and children on board, was shot up close to the town of Sermin in the northwestern province of Idlib, also near the border with Turkey, and 10 people were killed, said the Observatory.
Opposition activist Milad Fadl said the civilians were headed for Turkey when regime forces opened fire.
In Homs, also north of Damascus, “24 rounds of mortar fire have fallen since the morning on the districts of Bab Dreib, Safsafa et Warsheh,” the Britain-based Observatory said.
At least 62 people were killed in violence across Syria on Thursday, including 35 civilians, according to the Observatory. It said 18 soldiers and nine army deserters were among the dead.
The reports could not be confirmed due to restrictions on the movements of foreign media.
In the diplomatic front, U.N.-Arab League envoy Kofi Annan will travel this weekend to Moscow and Beijing to discuss the crisis in Syria, his spokesman said Friday, adding that a team sent to Damascus has returned.
The team is back after “three days of intensive talks with Syrian authorities on urgent steps to implement” Annan’s proposals on halting the violence. “Mr Annan and his team are currently studying the Syrian responses carefully, and negotiations with Damascus continue,” added the spokesman.
Monitors say more than 9,100 people have been killed in Syria’s unrest that started with peaceful protests in March 2011 before turning into an armed revolt, faced with a brutal crackdown which has cost dozens of lives each day.