A leading rights group has called on the Arab League to suspend Syria, and accused its government of crimes against humanity.
The US-based Human Rights Watch released a report alleging torture and unlawful killings in the central city of Homs, the BBC reported.
The watchdog said it carried out more than 100 interviews with witnesses and victims in Homs, which its Middle East director, Sarah Leah Whitson, said was a “microcosm of the Syrian government's brutality".
She told the BBC:
"The Arab League needs to tell President Assad that violating their agreement has consequences, and that it now supports Security Council action to end the carnage."
The Human Rights Watch report comes as dozens more protesters were reportedly killed, with fresh footage showing clashes between security forces and armed opposition fighters.
Activists said government troops fired on civilians on Thursday during raids aimed at finding dissidents in several parts of the country, including Homs, further north in Hama, Idlib near the Turkish border and the capital Damascus, Al Jazeera reported.
Read more on GlobalPost: Syria: The cost of repression
On November 8, the United Nations said the death toll in Syria after eight months of protests had passed 3,500 people. The civilian deaths were reportedly tallied from outside Syria, using sources on the ground.
The UN said the crackdown on protests had continued despite an agreement by Syrian authorities in early November to withdraw their tanks from restive cities, free political prisoners and hold talks with the opposition.
The government of Bashar Al-Assad blames the violence on what it calls “armed gangs and militants”.