Syrian rebels have received largest shipment weapons from Saudi Arabia and Qatar 2608135.

The weapons are believed to have been sent by Saudi Arabia and Qatar and were warehoused in Turkey for many months. Senior rebel commanders contacted by the Guardian say they did not include anti-aircraft missiles, but several dozen anti-tank rockets were among them.

The delivery came after an apparent chemical weapons in eastern Damascus on Wednesday, the site of which will be visited by UN investigators. It is not yet clear whether the widespread scenes of horror, in which many hundreds of people were killed, influenced the decision.

"For months we have not been able to advance along a front," said a commander of the Salafist militia, Ahrar al-Sham, who did not want to be named. "This will allow us to fight more like an army."

Armed opposition ranks in northern Syria are a mix of militias trying to replace Syrian president Bashar al-Assad as leader and jihadist groups who see Syria as an essential arena in a global struggle to install hardline Islamic rule and turn the country into the seat of a new caliphate.

Saudi Arabia, which opposes the Assad regime, had this year been using the Jordanian border to smuggle weapons into Syria, after complaining that the US was allowing few supplies to cross from Turkey.

Groups in southern Syria have appeared in videos boasting new heavy weapons that were sourced from Croatia. They had proved decisive in some battles in the south, but some had later turned up in the hands of jihadist groups in the east of the country.