A total of 12 people were killed across Syria in a new wave of violence on Friday, state-run SANA news agency reported.

Eight members of the government forces, including a major, were killed when armed groups attacked a police van carrying inmates at the Hussainiah suburb of the central province of Homs, said SANA, adding that a number of "terrorists" were killed in the shooting.

Another law-enforcement member was killed and two others were injured by armed men who opened fire at the national hospital in the Qusair district of Homs, the provincial capital city of Homs and Syria's third largest city, which has emerged as the hub of armed insurgency against the rule of President Bashar al-Assad.

In another area of Homs, two civilians were killed and another eight were wounded by the gunfire of a sniper nesting on a rooftop of a building at Iskandaroun street, said SANA.

In central Hama province, armed groups attacked a bus of workers in the Muharda area, killing one and injuring another, according to SANA.

In the Damascus suburb of Darayya, an explosive device went off, leaving a mother and her son, along with a taxi driver, injured.

On the opposition side, some Arab TVs cited an activist network, the Local Coordination Committees, as saying that 45 people were gunned down by government forces on Friday. It said most of the casualties occurred in Homs, adding that 12 of them were defectors and were executed in southern Daraa province, the birthplace of the anti-government movement.

The opposition's report could not be independently verified.

The Syrian government has blamed the unrest in the country on plots by terrorists and foreign-backed armed gangs, and said that more than 2,000 army and security personnel were killed during the past months.

The United Nations recently put the death toll in the Syrian unrest at around 6,000.