BEIRUT — Turkish warplanes shot down a Russian jet Tuesday after NATO-member Turkey says the plane violated its airspace on the border with Syria, a major escalation in the Syrian conflict that could further strain relations between Russia and the West.

Russian officials confirmed that a Russian Su-24 fighter had been shot down, but insisted it had not violated Turkish airspace.
“A stab in the back,” complained Russian President Vladimir Putin.

Turkey’s military, however, said that the Russian jet was warned multiple times before it was shot down by two F-16 fighter jets in the border zone in western Syria in mountains not far from the Mediterranean coast