Activists say rebels fighting to break a Syrian government siege of the opposition-held suburbs of Damascus have clashed with soldiers in battles that left over 70 dead on both sides.

Rami Abdurrahman of the British-based Syrian Observatory for Human Rights and an activist based in the nearby Qalamoun region said Sunday that the fighting happened overnight. It's a high toll for a one-day battle.

Abdurrahman said rebels included foreign fighters loyal to al-Qaida and the government forces included gunmen from Lebanon's Shiite militia Hezbollah. He said at least two Syrian media activists were also killed as they covered the clashes.

There was no word on the battle from government media.

President Bashasr Assad's forces blockade rebel-held areas where they can, to starve out civilians and pressure fighters into surrendering.