BEIRUT (AP) — Syrian government aircraft on Saturday pounded a rebel-held city in the country’s northeast, killing at least 12 people including five children, activists said.

The Britain-based Syrian Observatory for Human Rights said the air raids — seven strikes in total — hit the northeastern city of Raqqa early afternoon. Four women were among the dead and dozens of people were wounded, the Observatory said.

Rebels captured Raqqa, the capital of the province of the same name, in March. It’s the only major urban center to fall entirely under opposition control since the Syrian conflict began in March 2011.

Rebels also control territory in the north and parts of Aleppo, Syria’s largest city and its commercial center.

President Bashar Assad’s forces have relied heavily on air power in the last year to regain control of opposition-held territory, particularly in the north and along the border with Turkey.

Last week, at least 50 people were reported killed in two helicopter attacks on a rebel-held town near Aleppo.

Activists say airstrikes often precede government ground offensives. Assad’s troops may be mounting a major operation to recapture territory and bolster its position ahead of peace talks planned for January in Geneva.

Assad’s control of Syria’s skies is hampering rebels’ efforts to hold on to territory they capture and administer it with any efficiency.

Syrian conflict started as largely peaceful protests against Assad’s rule. Over the past year, it turned into a full-fledged civil war in which at least 120,000 people have been killed, activists say.

In western Syria, government troops backed by Hezbollah fighters were battling al-Qaeda-linked rebels for control of a town located along the country’s main north-south highway, according to the Observatory, which obtains its information from a network of activists on the ground.

The road holds strategic value for both sides, and serves as a crucial link between the capital Damascus and northern Syria as well as government strongholds along the Mediterranean coast.

The Organization for the Prohibition of Chemical Weapons said this week it would consider using the highway to transport Syria’s chemical weapons to the port of Latakia before they are taken out of the country for destruction.

Saturday’s clashes are concentrated around the town of Nabek. The section of the highway near the town has been closed for 18 days because of the heavy fighting, the Observatory said.