Fighters now use surface-to air-missile that can down Mi-8 helicopters, as opposed to machine guns.

Syrian opposition fighters have been acquiring more weapons and new capabilities, as they take over more military bases.

Over the past few months, rebels have used mainly machine guns to shoot down several Syrian air force helicopters and attack jets.

But last week, a video showed rebels using surface-to air-missile to down an Mi-8 helicopter.

Al Jazeera’s Kristen Saloomey reports.