A car bomb has reportedly exploded near a police station in Damascus, killing at least eight members of Syria's security forces.
The Syrian Observatory for Human Rights said the bomb went off on June 2 in Jubar district where clashes between regime forces and rebels were taking place.
The London-based group said the attack appeared to have been carried out by the Al-Nusra Front, an Islamist militant opposition group.
State media did not report the blast.
On June 1, fierce fighting was reported in and around Qusair, as forces loyal to Syrian President Bashar al-Assad tried to recapture the town near the border with Lebanon.
The UN Emergency Relief Coordinator, Valerie Amos, and the UN High Commissioner for Human Rights, Navi Pillay, said as many as 1,500 wounded civilians in Qusair need to be evacuated for medical treatment.
Based on reporting by AFP and dpa