Syrian rebels have shot down a military helicopter east of the capital Damascus, according to British based observers.
The new attack comes hours after rebels seized an air defence base nearby.
A video uploaded to social media sites purportedly shows dozens of rebels celebrating the capture of the base in the Eastern Gouta area and what they claim is a cache of surface-to-air missiles.
Also on Friday, the city of Homs, the nerve-centre for the rebellion against President Bashar al-Assad, saw the worst shelling in months, according to activists.
The neighbourhood of Khaldiyeh was apparently targeted for the first time by Syrian army warplanes.
In eastern Syria, locally-based activists say the town of Deir Ezzor saw similar air strikes on Thursday. Again unverified footage is said to show heavily damaged buildings still on fire.
More than 30,000 people have been killed during the 19 month old uprising.