"A total of 9,113 people have been killed, including 6,645 civilians," the Syrian Observatory for Human Rights said.

"The remaining deaths consist of 1,997 soldiers and security service agents, and 471 army defectors," the head of the Britain-based group, Rami Abdel Rahman, said.

The new toll was released as the uprising in Syria entered its second year, with pro- and anti-government demonstrations held around the country.

Despite a growing chorus of international condemnation, the regime has pressed on with its deadly crackdown against the revolt, which began as a peaceful protest movement but has evolved into an armed insurgency.