Rebels shot down Saturday a government warplane over western Syria, rebels and a military source said, although there were conflicting accounts on whether it had been brought down by a missile or anti-aircraft guns.

The Syrian military source said militants had targeted a warplane while it was landing in Hama province, bringing it down, and calling the attack a breach of the "cessation of hostilities" agreement.

A rebel group operating in the area, Jaish al-Nasr, said it had brought down the jet with anti-aircraft guns. The Syrian Observatory for Human Rights, however, said a rebel group had brought down the jet with two heat-seeking missiles.

Syrian rebels have previously shot down Syrian warplanes with anti-aircraft guns.

They have called on their foreign backers, including Saudi Arabia, to supply them with anti-aircraft missiles to confront Syrian and Russian warplanes. But they say these weapons have so far not been provided, reflecting concerns that they could end up in the hands of outfits such as Islamic State group.