The Turkish military reportedly shot down a Russian jet that it says violated its airspace on Tuesday.
Turkey says the plane reportedly didn't respond to repeated warnings.
The jet was carrying two pilots, both of whom reportedly ejected with parachutes. Turkmen rebels in Syria, which have close ethnic and historical links to Turkey, claim that they have shot both pilots dead.
Russian President Vladimir Putin called the act a "stab in the back by the associates of terrorism" and said the jet was shot down with surface-to-air missiles.
Here's video footage of the plane being shot down: