Syrian rebels launched a dawn offensive to take control of a key airbase in the country's north, activists have said.
The Syrian Observatory for Human Rights say rebels and government troops are fighting over the Taftanaz air base.
Activist videos posted online claim to show the attack on Taftanaz.
The video apparently shows the Free Syrian Army launching rockets towards the military airport in Taftanaz.
One of the rebels is heard to say, "operation to liberate the military airbase in Taftanaz".
Another video claims to show warplanes flying over Taftanaz from the base the rebels have attacked.
The Associated Press said the videos appear genuine and are consistent with their other reporting in the area.
Taftanaz lies near the highway between the capital Damascus and the northern city of Aleppo, a major front in the civil war.
Activists say more than 36,000 people have been killed in Syria since the uprising began in March 2011.
ITV News cannot independently verify the content of these videos.