Syrian rebels launched deadly attacks on the military on Saturday, Sept 1 in a campaign increasingly targeting its air power, as Russia said it was "naive" to expect President Bashar al-Assad not to fight back, AFP reports.

Rebel fighters captured the main air defense building in Albu Kamal on the Iraqi border, the Syrian Observatory for Human Right said, adding that "preliminary reports" suggested they had seized ground-to-air missiles that could boost their ability to down government aircraft.

The assault late Friday came hot on the heels of a rebel attack on the Abu Zohur air base in Idlib province in the northwest, where the Free Syrian Army said it downed a MiG warplane shortly after takeoff earlier this week.

In their assault in Albu Kamal, rebel fighters also captured 16 air defense personnel and attacked the nearby Hamdan air base, the Syrian Observatory said.

They were among a total of 125 people killed in violence nationwide on Friday - 74 civilians, 29 soldiers and 22 rebels, according to the Observatory's figures.