Turkey shot down a Russian warplane near the Syrian borderon Tuesday, saying the jet had violated its air space, in one of the most serious publicly acknowledged clashes between a NATO member country and Russia for half a century. <br />Russian President Vladimir Putin said the plane had been attacked when it was 1 km (0.62 mile) inside Syria and warned of "serious consequences" for what he termed a stab in the back administered by "the accomplices of terrorists". <br /> <br />"We will never tolerate such crimes like the one committed today," Putin said, as Russian and Turkish shares fell on fears of an escalation between the former Cold War enemies.
