Syria's elite Republican Guard has clashed with rebels outside Damascus in some of the most intense fighting involving the special forces since the uprising against president Bashar Assad began.
The battles erupted near Republican Guard housing compounds and bases in the suburbs of Qudsaya and Hammah, about five miles from central Damascus, the Britain-based Syrian Observatory for Human Rights said.
The Republican Guard, commanded by Assad's younger brother Maher, is tasked with protecting the capital, the seat of the regime's power.
Although Damascus is under the firm control of Assad's forces, clashes erupt regularly in the suburbs between troops and rebels, but it is rare for fighting to take place near the Republican Guard bases.
The Observatory and the Local Co-ordination Committees, another activist network, said troops stormed the Damascus neighbourhood of Barzeh with armoured personnel carriers, killing at least one person. Elsewhere in Syria, the LCC reported intense shelling in the eastern city of Deir el-Zour that wounded a number of people.
As Assad's crackdown on the uprising mutates into a civil war, fears are mounting that the violence could ignite regional unrest. Syrian activists say that more than 14,000 people have been killed since the crisis began in March 2011.
Meanwhile Syria's state-run news agency said Syrian troops killed 10 "terrorists" in the Damascus suburb of Douma.
The Syrian government refers to rebels as terrorists.