Beirut Syrian troops opened fire on anti-regime protesters in Damascus Friday rday a day after twin bombings killed dozens in the capital. "Five civilians were wounded when regime troops opened fire in the Tadamon neighbourhood" of the capital, said the Syrian Observatory for Human Rights.

"Some of the wounded are in a critical condition," activist Mohammad Al Shami told AFP via Skype.

Thousands of people were taking part in demonstrations across Syria yesterday, a day after the deadliest bomb attacks of the 14-month uprising against President Bashar Al Assad's regime struck the capital.

In Hama province of central Syria, troops shot and wounded 20 demonstrators in the town of Helfaya, where two civilians were killed in a raid, according to the Britain-based Observatory.

In Aleppo, where anti-regime sentiment has escalated in the past month, "many people were wounded by regime forces during demonstrations" across the northern city, activist Mohammad Al Halabi told AFP via Skype.

"Protesters denounced the failure of the international community to protect the Syrian people and renewed calls for immediate military intervention," Halabi added.

Thursday's twin bombings have raised fears that extremist elements could be taking advantage of the deadlock in Syria to stoke the unrest.

World powers condemned the attacks that targeted a military intelligence building and urged both sides to the conflict to adhere to the ceasefire brokered by UN-Arab League envoy Kofi Annan.

The 15 UN Security Council members urged the regime and rebels to "immediately and comprehensively" implement Annan's six-point peace plan, "in particular to cease all armed violence".

UN leader Ban Ki-moon, who earlier this week warned of possible civil war if Annan's plan failed, also renewed a call for all sides to cease violence and "to distance themselves from indiscriminate bombings and other terrorist acts."

Syria's UN envoy, meanwhile, said British, French and Belgian nationals were among foreign fighters killed in the country's escalating conflict and that there was Al Qaida involvement.

Ambassador Bashar Jaafari told the Security Council that 12 foreign fighters had been killed and 26 detained in recent clashes.