Syrian state television has quoted a military official saying the plane shot down by Turkey was pursuing rebel fighters within Syria's own territory.
The Turkish Prime Minister has said the jet was shot down because it had violated Turkish air space.
More top news
Air pollution released decades ago could still be causing deaths today, according to a new study.
Democrat presidential hopeful Hillary Clinton begins her New Hampshire campaign but young and female voters are opting for Bernie Sanders.
Some southern counties have seen their windiest winds of the winter so far today.