"Jihadists from the Al-Nusra Front and Islamist rebels attacked a regime checkpoint today morning at the entrance to Maalula, killing eight soldiers," the Syrian Observatory for Human Rights reported.
The group, which relies on a community of activists, doctors and lawyers on the ground for its information, said the assault kicked off when a vehicle driven by a suicide bomber exploded in front of the checkpoint.
The rebels then fought against soldiers from the army, it added.
A resident of Maalula, a picturesque town 55 kilometres north of Damascus that sits nestled under a large cliff, told AFP the Al-Nusra Front jihadists had started firing on the town at 0300 GMT.
More From This Section
Speaking by phone from the Mar Takla monastery, the woman who refused to be identified, said the rebels used shells and anti-aircraft machine guns, adding that some projectiles had hit the town centre.
Maalula is a symbol of the Christian presence in Syria, and many of its inhabitants speak Aramaic, the language spoken by Jesus Christ that only small, scattered communities around the world still use today.
It is full of troglodyte caves dating back to the first centuries of Christianity, and also houses the Mar Takla Greek Orthodox monastery.
More than 110,000 people have been killed since the conflict broke out in March 2011 with an uprising against the Assad regime, including over 40,100 civilians, according to the Syrian Observatory for Human Rights.