A video posted on YouTube claims to show Syrian rebels launching rockets towards the military airport in Taftanaz.
One of the rebels is heard to say, "operation to liberate the military airbase in Taftanaz".
Taftanaz lies near the highway between the capital Damascus and the northern city of Aleppo, a major front in the civil war.
This is the start of one of their more concentrated attacks on Syrian military power, according to rebels.
Syrian rebels launched a dawn offensive to take control of a key airbase in the country's north, activists have said.