BEIRUT — Syrian activists say warplanes have hit rebel positions near a contested military air base in the northern province of Aleppo.

The Britain-based Syrian Observatory for Human Rights says that fighter jets struck near the Kweiras air base early Tuesday. The group, which relies on a network of informants inside Syria, also reported heavy clashes in the area.

Opposition forces fighting to oust President Bashar Assad's regime have been trying for months to take the Kweiras complex located near the border with Turkey. The opposition has controlled large swathes of land in the north and whole neighborhoods inside the city of Aleppo since last summer.

Tuesday's airstrikes are part of Assad's campaign to reclaim territory the regime lost to the rebels in the past year.