One video purportedly showed rebels driving armoured vehicles at Taftanaz'
Rebels are reported to have taken control of a strategic military airbase in north-western Syria after days of fierce fighting with government forces.
Opposition activists said the Free Syrian Army (FSA) was in full control of Taftanaz airport. Videos purportedly showed fighters inside the facility.
Helicopters based there have been used to attack rebel-held areas.
Meanwhile, top US and Russian officials are attending talks in Geneva with the UN envoy to Syria, Lakhdar Brahimi.
They were expected to discuss how to advance a peace plan proposed by world powers in June, but the BBC's Imogen Foulkes says a diplomatic breakthrough is unlikely.
Ammunition store Hundreds of FSA fighters - led by the jihadist groups al-Nusra Front, Ahrar al-Sham and the Islamic Vanguard - have besieged Taftanaz Military Airport in Idlib province since early November.
Helicopters based at the sprawling facility, which lies near the motorway between the capital Damascus and the second city of Aleppo, have been used to bomb rebel-held areas in the north and deliver vital supplies to government forces struggling to halt rebel advances.
Rebel fighters broke into the airbase on Wednesday night after days of fighting, and by Thursday had seized control of more than half of it.
