Insurgent groups attacked several Syrian government positions in Hama province on Thursday in what a rebel commander said was the biggest rebel assault in the area since a cessation of hostilities agreement came into effect two weeks ago.
There were conflicting accounts about the outcome of the attack and who carried it out. The Syrian Observatory for Human Rights said the attack failed with at least 20 of the attackers killed, describing them as Islamists including foreign fighters.
Fares al-Bayoush, head of a Free Syrian Army group called the Northern Division, said the attack was carried out by "local groups." He called it a response to "violations that happened by the regime during the truce" and said two positions were captured.
Syrian state TV said the attack was mounted by the al Qaeda-linked Nusra Front, which is not included in the cessation agreement. It said the assault failed with 70 militants killed.
Rami Abdulrahman, director of the Observatory, described it as a "comprehensive attack."