An al-Qaida-linked group fighting alongside Syrian rebels has claimed responsibility for a suicide car bombing a week ago that reportedly killed dozens of President Bashar Assad's loyalists.

A statement Monday from Jabhat al-Nusra says one of its suicide bombers detonated a car bomb at the headquarters of a pro-government militia in the central province of Hama.

Activists said at least 42 people, mostly pro-Assad militiamen, died in the blast last Monday in the town of Salamiya. The government did not say how many people were killed.

Al-Nusra is fighting alongside other rebels to topple Assad. The group has previously targeted government institutions with suicide bombers.

The U.S. says it's linked to al-Qaida, and has declared the group a terrorist organization.