A spokesperson said the downing of the plane was a 'very serious incident' but added it was too early to draw any conclusions.

Turkey said the jet was warned 10 times in the space of five minutes before it was shot down. Television footage released by Turkey's state-run Anadolu news agency appeared to show two pilots parachuting out of a jet downed near the Turkish-Syrian border. Turkish F-16 fighter jets shot down the war plane, a Russian-made SU-24. However Russia has claimed the plane remained in Syrian airspace for the duration of its flight.