A prominent Druze cleric known for criticising Syria's regime and Islamist extremists was assassinated in a car bomb attack outside the southern city of Sweida Friday, a monitoring group said.

"Sheikh Wahid al-Balous was killed in a car bomb attack as he was driving on the outskirts of Sweida city. The bomb also killed three other people," said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights.