Russia fans the flames as aircraft cross into Ukraine

Kiev protests to Moscow as UN convenes emergency session

Soldiers, who were wearing no identifying insignia and declined to say whether they were Russian or Ukrainian, patrol outside Simferopol International Airport in Crimea

Roland Oliphant and David Blair

Russian military helicopters crossed into Ukraine and were flying towards Crimea last night as the confrontation over the crisis-torn region took a dramatic new turn.

The UN Security Council was preparing to convene an emergency session on the escalating crisis at the request of the government in Kiev, which warned that its territorial integrity was being threatened.