BEIRUT -- Syrian fighter jets on Sunday bombed Damascus suburbs in a government offensive to dislodge rebels from strategic areas around the capital, activists said, as clashes raged around army bases and airfields in the country's north.

The Britain-based Syrian Observatory for Human Rights said warplanes were hitting towns and villages around the capital, including Kfar Batna and Gesereen, while regime forces targeted other neighborhoods with artillery and mortars. At least nine people were killed when a shell hit eastern Ghouta district, the group said.

It also said troops were battling rebels in the suburb of Daraya a day after government officials claimed the army had taken much of the strategic area, which lies on the edge of a major military air base southwest of the capital.

In northern Syria, government forces were fighting rebels over an air base and the international airport of the city of Aleppo. The airport includes a military base.

Syrian troops have been pushing since November to regain Daraya, which had a population of about 200,000 before the fighting. Thousands have fled the relentless violence, among more than 2 million Syrians who have been internally displaced during the civil war. At least half a million Syrians have fled to neighboring countries like Turkey, Lebanon and Jordan.

Observatory director Rami Abdul-Rahman said government troops now control more than half the suburb, a stronghold of support for the rebels since the start of the uprising against President Bashar Assad in March 2011.

Because of its strategic location, rebel control of the Daraya poses a particularly grave threat to the capital. The suburb is flanked by the key districts of Mazzeh, home to a military air base, and Kfar Sousseh, where the government headquarters, the General Security intelligence agency head office and the Interior Ministry are located.