The Syrian conflict has bred the emergence of obscure jihadists carrying out bloody attacks, either acting independently or manipulated by the regime seeking to tarnish the image of its opposition, analysts say.
"Al-Qaeda does not exist in Syria. But there are at present several splinter groups of jihadists who employ the same strategies," said Mathieu Guidere, a France-based analyst who specialises in the Arab and Muslim world.
"We know that these are Syrians, not foreigners, and that they are very few. For now, nobody knows them -- neither Al-Qaeda nor the rebels," he added.
On May 10, twin suicide bombings in Damascus killed at least 55 people and wounded 372 -- the deadliest attacks since the uprising against President Bashar al-Assad's regime erupted in March 2011.
Al-Nusra Front, an Islamist group unknown before the Syrian revolt, claimed responsibility for the bombings as well as previous attacks in the capital and in the northern city of Aleppo.
"Law and order are also breaking down in Syria, which means that we should expect the spread of radical groups," Middle East analyst Joshua Landis writes in his blog.
Whatever their identity, the perpetrators of these attacks are "using signature Al-Qaeda tactics," said Guidere, adding that "simultaneous attacks are the trademark" of the network founded by Osama bin Laden.
The escalation of violent attacks, reminiscent of those carried out in neighbouring Iraq and claimed by extremist groups linked to Al-Qaeda, have raised fears of an "Iraqisation" of Syria.
Washington, which has long accused Damascus of turning a blind eye to extremists crossing through the Syrian border into Iraq, has refused to supply arms to the rebels, lest they fall into the hands of Al-Qaeda.
In the absence of any evidence about the sponsors of the attacks, Guidere, author of several books on Al-Qaeda, proposes two hypotheses:
"It could be splinter groups who, like Somalia's Al-Shabab (Islamist insurgents), want to be recognised as Al-Qaeda."
"The second and more credible hypothesis is that these groups carry out -- or are made to carry out the attacks -- so that the general public confuses them with Al-Qaeda," he added.
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The latest bombings primarily benefit the Syrian regime, analysts say, which, from the start of the 14-month revolt, has described the uprising as a Western-backed Al-Qaeda plot and its opponents as "terrorists" to justify its crackdown.
"Bashar al-Assad has said: 'If anybody dares to challenge my rule, there will be chaos.' What he said is becoming a self-fulfilling prophecy," said Salman Shaikh, director of the Brookings Doha Center.
Shaikh noted there was no clear link between the regime and the bomb attacks, as the opposition has charged, "but at the end of the day, the responsibility lies with the regime because it has pursued only a security approach."
"It is the regime who created this environment and the international community has allowed the situation to drift," he added.
Shaikh added that a small group like Al-Nusra Front would not be able to pull off such "sophisticated" attacks without the help of "much more professional forces."
Would the rebels, frustrated by the impasse of the conflict, have resorted to terrorism?
Al-Qaeda leader Ayman al-Zawahiri has openly expressed support for the Syrian revolt, something which the rebel groups have rejected as "interference."
This type of attack could not benefit the rebels, who have no interest in being linked to Al-Qaeda," Guidere said.
International Crises Group said the regime appeared to stand to gain the most from the mayhem.
"Some observers suspect a regime hand in events that served its interests: damaging its foes' image; mobilising and radicalising its own popular base; frightening the many Syrian fence-sitters; and heightening Western reluctance to become involved in a muddled and messy conflict.
"The blasts almost certainly produced all those effects," it said.
Despite the Islamist rhetoric adopted by many rebels and opposition figures, analysts point out that the agenda of Syria's Muslim Brotherhood bears no relation to the jihadist militancy of Al-Qaeda.
"We know the traditions of Islamists of Al-Qaeda. These guys are doing it out of ideology ... The Muslim Brotherhood or even Salafists are very different," said Shaikh. "It is like oil and water, the two don't mix."