Syria's opposition said Tuesday that a military mutiny in the town of Jisr al-Shaghur is behind the recent violence that left more than 120 people dead, DPA reported.
The government said armed groups attacked security forces and a security post and set fire to government buildings on Monday, leaving up to 123 policemen dead.
But exiled opposition members who help the transport of injured civilians from Idlib province to Turkey told the German Press Agency dpa that the soldiers and police officers killed were shot because they refused to fire upon unarmed civilians in the town.
Al-Jazeera broadcaster has aired a video of a uniformed soldier. In it, the soldier says he has defected and calls on other army members to follow him.
The Syrian military has been attacking the town of Jisr al-Shaghur since last week as part of a crackdown to halt the uprising against the regime of President Bashar Assad.
More than 1,300 people have been killed since the unrest began in March, according to rights groups.
Demonstrations calling for al-Assad's ouster and an end to violent government crackdowns on protesters were held in various parts of the country late Monday.
Hundreds of people participated in a nightly demonstration in other towns in Idlib, with people carrying olive branches and chanting for Jisr al-Shaghur town.
They were chanting "Syrian people are united," the Local Coordinating Committee in Syria, an online group reported.
Al-Assad, who inherited his post after his father's death in 2000, faces rising public anger and international sanctions as the death toll grows.