A suicide car bomb went off Monday evening in front of the Syrian air force intelligence compound at the Harasta suburb of the capital Damascus, sources said.
Intense clashes have followed the blast and are still raging on, the sources said, however, no reports of casualties have emerged with the absence of official comments.
Some pro-government media said the guards of the security installation have suspected the car and showered it with bullets before the suicide bomber detonated himself.
Meanwhile, witnesses said that the blast was so strong that other adjacent suburbs heard the big boom.
Earlier, a pro-government Syrian radio said a suicide car bomb went off at Harasta suburb of Damascus overnight Monday.
Such blasts have become increasingly common recently at a time the Syrian troops is carrying on with wide-scale offensives nationwide to root out armed insurgency that have become rampant nationwide.
The last blast occurred Sunday evening, when a booby-trapped car ripped through the garage of the police headquarters in the capital Damascus and killed one police member.