Rebels and government have been fighting in and around Damascus for months
Warplanes have bombarded a district housing Palestinian refugees in the Syrian capital for the first time since the anti-regime uprising began, activists have said.
Initial reports on Sunday suggested that a mosque sheltering people who had fled violence in nearby suburbs was hit and several people were killed.
Video posted online, purporting to show the aftermath, showed several bodies and destruction.
"Warplanes staged an airstrike on an area near al-Bassel hospital... in Yarmouk camp, hurting several people," the UK-based Syrian Observatory for Human Rights said.
The district has seen clashes between government troops and rebels and been bombarded earlier in the conflict but Sunday was the first time air power was used, according to activists.
Yarmouk is a residential area where Palestinians and Syrians from the Israeli-occupied Golan Heights have lived for decades. Since violence intensified in and around Damascus in summer, residents from nearby neighbourhoods which have seen intense fighting between rebels and government troops have taken shelter in the area.
As the Syrians, Palestinians have been divided over the uprising, with some taking up arms against the regime and others fighting to defend it.