Former White House adviser Pat Buchanan has added his voice to the growing chorus of critics who say chemical weapons attacks in Syria were carried out by rebel groups, with the possible connivance of the West and its allies in the region.

Buchanan, a broadcaster and political commentator who advised the Republican administrations of Presidents Nixon, Ford and Reagan, echoed former member of Congress Ron Paul in labelling the attacks a "false flag".

"First, this thing reeks of a false flag operation," Buchanan said in an interview with Newsmax.

"I would not understand or comprehend that Bashar al-Assad, no matter how bad a man he may be, would be so stupid as to order a chemical weapons attack on civilians in his own country when the immediate consequence... might be that he would be at war with the United States. So this reeks of a false flag operation."

Earlier in the week, Paul used the same phrase to blame al-Qaida for the use of chemical weapons, saying the attack was part of a plan to draw the US into "strife that's been going on in that region for thousands of years".

Paul told Fox Business: "I think one of the reasons why they say, well, this is not regime change is because we're not really positive who set off the gas. The group that's most likely to benefit from that is al-Qaida.

"They, you know, ignite some gas, some people die and blame it on Assad. Assad, I don't think, is an idiot. I don't think he would do this on purpose in order for the whole world to come down on him."

Reports have surfaced of al-Qaida-backed rebels in the Damascus suburb of Ghouta apparently admitting they had carried out the chemical attacks.

Associated Press correspondent Dale Gavlak claimed rebels admitted to perpertrating the attacks with weapons supplied by Saudi Arabia.

"More than a dozen rebels interviewed reported that their salaries came from the Saudi government," said Gavlak.

The rebels claimed the large-scale casualties were caused by rebels mishandling chemical weapons, which were intended for the al-Qaida-linked splinter group the al-Nusra Front.

'Saudi factory'

The claims would appear to support comments by Syria's deputy foreign minister, Faisal Mekdad, who blamed "terrorists" for the use of chemical weapons. Others have claimed that the alleged chemical weapons bore markings from a "Saudi factory".

Gavlak said rebels told him they had received no advice on how to handle the weapons, or what they contained.

"We were very curious about these arms. And unfortunately, some of the fighters handled the weapons improperly and set off the explosions," one militant identified as "J" is alleged to have told Gavlak.

The account was supported by another female fighter, "K", who told Gavlak: "They didn't tell us what these arms were or how to use them. We didn't know they were chemical weapons. We never imagined they were chemical weapons."

According to Gavlak, Abu Abdel-Moneim, the father of an opposition rebel, said: "My son came to me two weeks ago asking what I thought the weapons were that he had been asked to carry."

The weapons were described as having a "tube-like structure", while others were like a "huge gas bottle".

Gavlak has been an AP correspondent in the Middle East for two decades, and has also worked for National Public Radio and the BBC.

The AP distanced itself from Gavlak's report, saying it had not published the article itself.

Saudi Arabia's role in arming the rebels is well documented. Earlier this week, reports emerged that Prince Bandar bin Sultan had attempted to cajole Russia into dropping its support for Syria through a mixture of diplomatic inducements and coded threats.

The prince was said to have secretly offered Russia a deal to control the global oil market and safeguard Russian gas contracts, if the Kremlin backed away from the Assad regime in Syria.

Bandar also hinted at Chechen terror attacks on next year's Winter Olympics in Sochi unless Putin abandoned support for the Syrian President, saying: "The Chechen groups that threaten the security of the games are controlled by us."

US intelligence officials have acknowleged the intelligence, proving Assad's guilt was "no slam dunk", while intercepted communications were said to show Syria's Defence Ministry making "panicked" phone calls to its chemical weapons department in the hours after the attack, demanding to know what had taken place.