Rebels in Syria say they have launched a major offensive to capture a key airbase in the north of the country.
Video posted on the internet shows fighters attacking the Taftanaz base as they aim to restrict the government's increasing use of air power.
The BBC reports the attack took place as dawn broke, with as many as five different units of rebel fighters reportedly opening fire with multiple rocket launchers, mortars and other weaponry.
Activists said the fighting was continuing into the evening, although state media said government forces had repelled the assault, killing a large number of rebels and destroying their vehicles.
In recent months, the government forces have been making increasing use of air power to strike areas held by the rebels, who lack anti-aircraft weapons to deter the attacks.
Rebel forces are reported to have taken control of the main roads in much of the area south-west of Aleppo.
