BEIRUT: Syrian rebels freed more than 100 inmates as they battled against regime troops in a major prison outside the northwestern city of Idlib on Saturday, a watchdog said.

At least 10 rebels were killed on Friday in clashes inside the prison, said the Syrian Observatory for Human Rights, which relies on a network of activists and medics in the war-torn country for its information.

"The rebels have been able to free more than 100 prisoners since fighting broke out on Friday, but they have not gained control of the prison," the Britain-based Observatory's director Rami Abdel Rahman told AFP by telephone.

Videos posted online by activists showed rebels inside the penitentiary, which is located at the western entrance of the provincial capital. The city remains under regime control, but Idlib province is mostly opposition-held.

Dozens of prisoners were shown escaping to an outdoor area of the prison, protected by rebels, as gunfire and explosions were heard in the background.

One man collapsed, bleeding profusely, and others were seen struggling to carry him along with them.

Other footage apparently from inside the prison, illuminated by a green night-vision light, shows bombed-out cells and dead inmates on the ground, who prisoners say were summarily executed by soldiers.

The videos could not be immediately verified.

The prison battle followed a day in which 168 people -- 63 soldiers, 60 rebels and 45 civilians -- were killed nationwide, the Observatory said.