DAMASCUS, Syria -- Two suicide bombers detonated their explosives packed vehicles near a cluster of commercial buildings in a suburb of Damascus Wednesday, killing at least 34 people and covering the street with pools of blood and debris.

The latest carnage to hit an area populated by religious minorities who support President Bashar Assad further raises concerns of a growing Islamic militant element among the forces seeking to topple him.

In the country's north, rebels claimed to have shot down a Syrian air force fighter jet, providing further evidence of their growing effectiveness and improved military capabilities. It was not immediately clear how the MiG-23 was downed, although activists and the Turkish state-run Anadolu news agency said it was most likely brought down by a missile.

The morning rush hour bombings in the suburb of Jaramana, just few kilometres (miles) southeast of Damascus, were the latest to hit the overwhelmingly pro-regime town. The twin blasts appeared designed to maximize damage and casualties and bore the hallmarks of radical Muslim groups fighting alongside other rebel units in Syria.

Witnesses said the second explosion went off after people rushed in to help those injured from the first blast, a tactic often used by al-Qaida in Iraq and elsewhere.

There was no immediate claim of responsibility for the bombings, but Jabhat al-Nusra, an al-Qaida-inspired extremist group that has become one of Syria's most potent and organized rebel groups, has claimed numerous suicide bombings in the past, mostly targeting regime forces and security installations.

Wednesday's bombs went off in a parking lot near commercial buildings as groups of labourers and employees were arriving for work, killing 34 and injuring 83 people, state-run news agency SANA said.

The blasts sent people fleeing in panic, shattering windows and littering the streets with glass, debris and pools of blood. Several commercial buildings were damaged, and dozens of cars were reduced to smouldering wreckage.

Ismail Zlaiaa, a 54-year-old resident of the neighbourhood, said the area was packed with rush-hour passengers when the suicide bombers struck.

"God will not forgive the criminal perpetrators," he said.

Ibtissam Nseir, a 45-year-old teacher, said the bombs exploded minutes before she set off for work. She said there were no troops around the district and wondered why the attackers would target it. She blamed the rebels.

"Is this the freedom which they want?" she asked.

Syria's conflict started 20 months ago as an uprising against Assad, whose family has ruled the country for four decades. It quickly morphed into a civil war, with rebels taking up arms to fight back against a bloody crackdown by the government. According to activists, at least 40,000 people have been killed since March 2011.

Opposition fighters are predominantly members of the Sunni Muslim majority. In their push to take Damascus, they have frequently targeted state institutions and troops. They have also often hit districts around the capital with the country's minority communities, perceived to be allied with Assad's Alawite sect, an offshoot of Shiite Islam.

Wednesday's twin bombings are the latest targeting Jaramana, a Christian and Druse area mostly loyal to Assad. Other car bombings have recently targeted areas of the capital Damascus dominated by the Alawite sect.

The rebel groups, an increasing number of Islamist extremists and foreign fighters among them, have found difficulties winning over the country's ethnic and religious minorities, including Christians and Kurds, as well as other groups that remain wary of an alternative to Assad.

Bombings such as Wednesday's are likely to rally his support base among those vulnerable minorities, reinforcing their concerns that the uprising against Assad was being driven by Islamic extremists.

The Assad dynasty has long tried to promote a secular identity in Syria, largely because it has relied heavily on its own Alawite base in the military and security forces in an overwhelmingly Sunni country.

Assad blames the revolt on a conspiracy to destroy Syria, saying the uprising is being driven by foreign "terrorists" -- a term the regime uses for the rebels -- and not Syrians seeking change.

The majority of those fighting Assad's regime are ordinary Syrians and soldiers who have defected. But increasingly, foreign fighters and militants adhering to an extremist Islamist ideology are turning up on the front lines. The rebels try to play down the Islamists' influence for fear of alienating Western support.

In northern Syria, a rebel group claimed it brought down a Syrian MiG-23 fighter plane near the rebel-held town of Daret Azzeh and captured its pilot, according to activists. A report by turkey's state-run Anadolu news agency quoting rebels in the area said the jet was shot down most likely by a missile.

Amateur video posted online by activists showed what appears to be the wreckage of the plane still on fire.

"O Bashar, this is your plane, it has become wreckage at the hands of the Free Army," says the video's narrator, adding it was shot down with a missile.

Another video showed a wounded man wearing what appeared to be an aviator's uniform being carried away. "This is the pilot who was shelling the homes of civilians," said the voice on camera.

The videos appeared to match activists' reports of what went on in the area.

Opposition fighters have shot down helicopters and claim to have brought down warplanes in the past, although the rebels repeatedly complain their arsenal is no match for the regime's fighter jets and attack helicopters.

In recent weeks rebels have captured several air bases with anti-aircraft weapons, but it is not known if they have the ability to operate them.

In other violence Wednesday a car bomb exploded in the southern village of Busra al-Hariri and regime warplanes struck rebel-held areas in the northern Idlib province and Damascus suburbs.