Four people were killed when a suicide car bomb went off in Syria's northern province of Qamishli on Sunday, the state news agency SANA said.

SANA gave no further details, but the blast came as part of the spiralling violence that has engulfed a considerable number of areas across Syria.

Earlier in the day, an explosive device affixed under a car went off at al-Baytara roundabout in the capital Damascus, amputating the hand of the driver and leaving material damage, sources told Xinhua.

The al-Baytara roundabout is close to a main intelligence headquarters in the area, which has been targeted more than two times by explosives.

Last week, the same area was hit by an explosive device that ripped through a boarding school the rebels claimed was being used by the Syrian security forces as a base.

The blast came as violence and clashes between the government troops and armed militias have engulfed some restive suburbs of Damascus.