AMMAN (Reuters) - Rebel suicide bombers struck overnight at an Air Force Intelligence compound on the edge of the Syrian capital Damascus, killing or wounding at least 100 people, insurgents and activists said on Tuesday.
The militant Islamist group al-Nusra Front said it had mounted the attack because it was used a centre for torture and repression in the crackdown on the 18-month-old revolt against President Bashar al-Assad.
"Big shockwaves shattered windows and destroyed shop facades. It felt as if a bomb exploded inside every house in the area," said one resident of the suburb of Harasta, where the compound was located.
Activists living nearby said the bombing caused at least 100 casualties among security personnel, based on the number of ambulances that rushed to the scene and the enormity of the explosions.
No official casualty figure was given. Security forces cordoned off the area and deployed snipers along routes leading to it.
Rebel fighters have carried out a series of bombings of government and military buildings in Damascus in recent months, bringing the war to the heart of Assad's power base.
The most notable was an attack on the National Security headquarters which killed the defence minister and two other senior security officials in July.
The latest bombing coincided with a series of rebel raids on roadblocks manned by Assad forces on a highway leading north from Harasta and in Sunni Muslim neighbourhoods of Damascus that have been at the forefront of the revolt, residents said.
Syrian warplanes also bombed areas near the town of Um al-Asafir on the edge of Damascus, and artillery pounded the suburb of Artous, killing at least one woman, according to opposition activists.
Residents and opposition activists told Reuters the attack set off huge explosions and was followed by a gun battle. Video footage taken by activists, which could not be independently verified, showed a large explosion.
"The decision was taken to hit Air Force Intelligence because it is one of the most notorious security divisions, and a citadel of repression whose extent is known only to God," said an Al-Nusra statement posted on social media.
The Airforce Intelligence unit is commanded by Brigadier General Jamil Hassan, one of Assad's senior lieutenants, and is mostly made up of personnel from the president's minority Alawite sect, an offshoot of Shi'ite Islam.
There was no information on whether Hassan was present during the attack.
Opposition activists said hundreds of Assad's opponents have been imprisoned without charge and tortured in the Harasta complexes.
The Syrian National Council Opposition group said in a statement that it was concerned about the fate of political prisoners in the compound.
Opposition sources said the al-Nusra Front is made up mostly of Syrian Salafists who had ties to intelligence agencies before the revolt and were allowed to use Syria as a launchpad against the then U.S.-backed, Shi'ite-led government in Baghdad.
The United Nations says the front is affiliated to al Qaeda.
"Al-Nusra is proving itself as the group capable of launching the most devastating attacks against the regime," a Western diplomat following the revolt said.
Reporting by Khaled Yacoub Oweis, Amman newsroom; Editing by Angus MacSwan