AMMAN- Western-backed Syrian rebels said they had shot down a Syrian military jet on Tuesday in a desert area in southern Syria near the border with Jordan, where the army had recently advanced and seized border posts. Saad al Haj, spokesman for the Osoud al Sharqiya rebel group leader, told Reuters the rebels had shot down the Russian-built MiG using anti-aircraft guns. "It was downed in Wadi Mahmoud in eastern Sweida countryside. The wreckage fell in the area and we think the pilot has dropped in a parachute. The search is going on to find him," said al Haj, whose group is one of two major rebel groups that operates in the area.The eastern countryside of Sweida province borders Jordan in a front where the Syrian army, alongside Iranian-backed militias, had established control last Thursday over checkpoints and border posts.Syrian officials could not immediately be reached for comment. Reuters could not independently confirm reports of the downed plane.Last month the same rebel alliance said a military jet had come down about 50 kms east of Damascus in a rebel-held territory near a frontline with army troops. Videos on social media were released of the remains of the pilot and wreckage said to be that of the warplane.