BEIRUT – Syrian rebels fully captured a northern town near the Turkish border on Tuesday after weeks of heavy fighting and attacked a regime air base in a neighboring province, activists said.

The air base is in Aleppo province, where opposition fighters already have captured three other large military bases in recent months. Rebels also have laid siege to the international airport in the city of Aleppo, Syria’s commercial capital, and launched an offensive on the police academy near the city.

With steady rebel gains across the north, President Bashar Assad’s regime is having increasing difficulty sending supplies by land to Aleppo province, especially after rebels cut a major thoroughfare from Damascus. It is just another sign that the opposition is consolidating its grip across large swathes of territory in northern Syria near the Turkish border.