A bomb blast in a Palestinian refugee camp in Damascus killed four people and seriously wounded a member of a faction that has backed Syrian President Bashar Assad in the country's bitter civil war, activists have said, according to Belfast Telegraph.

The explosion in the Yarmouk camp targeted the Popular Front for the Liberation of Palestine-General Command.

Four people died and a PFLP-GC activist was seriously wounded when the bomb planted under his car went off, the group said. It blamed the rebel Free Syrian Army for the attack.

Yarmouk was drawn into Syria's fighting earlier this month when clashes in and around the camp killed and wounded dozens.

The refugee camp is also close to two southern neighbourhoods of the capital - Tadamon and Hajar Aswad - that have seen weeks-long clashes between rebels and government troops.

Regime forces shelled the two neighbourhoods today and also raided the central Damascus neighbourhood of Bab Sreijeh, said the Britain-based Syrian Observatory for Human Rights. Activists said several people were arrested.

In other violence around the country, Islamic extremists, including members of the al Qaida inspired Jabhat al-Nusra group, battled with pro-government Kurdish gunmen in the northern town of Ras al-Ayan, near the border with Turkey.