Rebels shot down a second Syrian warplane in less than a month on Tuesday and reportedly captured its pilot in an area near Aleppo where heavy fighting has erupted in recent days despite a cessation of hostilities agreement.
The Syrian army said the jet was shot down with an anti-aircraft missile - the same type of weapon it says was used to shoot down a warplane in western Syria in March - but rebels accused Damascus of fabricating the claim, saying the plane was downed with anti-aircraft guns.
Foreign-backed rebels have long demanded anti-aircraft weapons to fight against devastating aerial raids by Syrian and, since September, Russian forces. But their backers, which include Western and Sunni Muslim regional states, are wary of delivering weapons that could fall into the hands of hardline groups.
The aircraft crashed in the Talat al-Iss highland south of Aleppo city, an area where al Qaeda-affiliated insurgents have come under heavy bombardment by Syrian and Russian warplanes since capturing it in recent days, the Syrian Observatory for Human Rights said.
The pilot was seized alive by fighters from al Qaeda's Nusra Front and taken to one of their headquarters in the area, the monitoring group said.
Videos circulated by pro-rebel accounts on social media showed what appeared to be the remains of the aircraft burning on an open patch of ground and surrounded by rebels. Some users separately posted an image of the man they said was the pilot.
Syria's military confirmed that a plane on a reconnaissance mission had crashed after being hit by a surface-to-air missile. The pilot survived and efforts were underway to rescue him, it said.