SYRIEN - En sammanställning av konflikten

Rebels fighting to depose Syrian president Bashar al Assad have for the first time acquired a small supply of surface-to-air missiles, according to a news report that a Western official did not dispute.

NBC News reported Tuesday night that the rebel Free Syrian Army had obtained nearly two dozen of the weapons, which were delivered to them via neighboring Turkey, whose moderate Islamist government has been demanding Assad's departure with increasing vehemence.

Indications are that the U.S. government, which has said it opposes arming the rebels, is not responsible for the delivery of the missiles.

But some U.S. government sources have been saying for weeks that Arab governments seeking to oust Assad, including Saudi Arabia and Qatar, have been pressing for such missiles, also known as MANPADs, for man-portable air-defense systems, to be supplied to the rebels.

In recent days, air operations against the rebels by Syrian government forces appear to have been stepped up, particularly around the contested city of Aleppo, making the rebels' need for MANPADs more urgent.

Precisely what kind of MANPADs have been delivered to Syrian rebels is unclear and NBC News did not provide details. Such weapons range from the primitive to highly sophisticated.

And even if the rebels do have the weapons, it is unclear whether they have the training to operate them effectively against Assad's air forces in the immediate future.