DAMASCUS, Dec. 12 (Xinhua) -- At least 34 people were killed Monday by airstrikes on rebel-held areas in central province of Hama, a monitor group reported.

Half of the killed were children, said the Syrian Observatory for Human Rights.

It added that the airstrikes targeted areas in town of Akeirbat in eastern countryside of Hama.

The UK-based watchdog group said it had cited sources as saying that the rockets fired from the war jets were stuffed with chemical material.

It said some of the people had suffered suffocation after the airstrikes, which have intensified on Monday after the Islamic State (IS) group stormed the nearby ancient city of Palmyra.

Meanwhile, the Observatory, which says it relies on a network of activists on ground, said the rebels in Hama fired rockets at a military airbase in the area, leaving unknown losses.