text: Two leading groups, Jaysh al-Islam and Ahrar al-Sham, which formed a pact last year, both say the plane was shot down.
  Syrian state media said the crash was caused by a technical fault.
  Jaysh al-Islam, the larger of the two groups, posted footage online which it claimed showed the pilot being held after ejecting from the jet.
  The video, bearing Jaysh al-Islam's logo, showed an object engulfed in flames followed by an interview with the supposed pilot.
  The man gave his name as Nawras Hassan, as well as his date of birth and hometown. He said he was based in Dumair air base and that he had been a pilot for 16 years.
  A later image posted by the group appeared to show the pilot dead.
  Jaysh al-Islam said in a statement that the pilot was captured by the Joint Operations Room - the name adopted by a collection of rebel groups in the region including Jaysh al-Islam, Ahrar al-Sham, and Jabhat al-Nusra.
  Jaysh al-Islam said the pilot was captured by militants from the al-Qaeda-linked Jabhat al-Nusra, who were supposed to hand him over but killed him instead.
  Neither the claims nor the footage have been independently verified.
  More than 280,000 have been killed and millions displaced by Syria's five-year conflict, according to UN estimates.
target: Syrian rebels say they shot down a Syrian air force jet and blamed an al-Qaeda-linked group for killing the pilot.