Updated Friday, November 23, 2012 at 05:54 PM
Activists say Syrian troops have shelled southern neighborhoods of the capital as they try to advance in rebel-held areas.
The Britain-based Syrian Observatory for Human Rights says the shelling of Tadamon and Hajar Aswad came as government troops conducted raids in the central Damascus neighborhood of Bab Sreijeh.
The violence came as Iran's parliament speaker Ali Larijani arrived in Damascus on Friday. He is expected to meet President Bashar Assad.
Iran is Assad's strongest ally in the region.
Syria's conflict erupted in March 2011 with an uprising against Assad's regime, inspired by other Arab Spring revolts. The crisis has since morphed into a civil war. More than 40,000 people have been killed in the unrest, according to activists.
DAVID ENDERS / MCCLATCHY NEWSPAPERS
A Syrian man stands next to the remains of a Syrian government cluster bomb, on November 21, 2012, outside of houses it destroyed in Mayadin, in southeastern Syria, on November 10.