Several people have been injured after an explosion hit a bus carrying security forces in Damascus. Residents say they heard a powerful blast, followed by the sirens of ambulances rushing toward Damascus's southern ring road near the neighbourhood of Midan.
Activists say the blast appeared to have been caused by an explosive device stuck onto the bus.
UN observers toured Tremseh for a second day as the Syrian government denied claims that its forces killed more than 100 people on Thursday.
An attack in Tremseh in Syria appeared to target the homes of army defectors and activists, a spokesman for the UN observers in Syria said.
The international community has come together in its condemnation of the Syrian regime after more than 200 civilians were killed in Hama.