Meshaal Tamo, 53, was killed by four masked gunmen who also wounded his son Marcel and a female fellow activist in the Kurdish Future Party, the Syrian Observatory for Human Rights said.

The opposition Local Coordination Committees group said Tamo "was killed on Friday at his home by unidentified men. His son as well as activist Zahida Rashkilo were wounded."

Thousands of Kurds took to the streets in Qamishli after Tamo's death was made known, and gathered outside the hospital where his body was taken.

The official SANA news agency reported "the assassination" of the Kurdish activist, but gave a different account of his death. It said he was killed "by gunmen in a black car who fired at his car."

Tamo was a member of the newly formed Syrian National Council (SNC) opposition grouping. He had been released recently after spending three and a half years in prison.

He founded the liberal Kurdish Future Party, which considers the Kurds to be an integral part of Syria.