‘This is a declaration of war . . . We are on the brink of disaster’

“This is a declaration of war... We are on the brink of disaster,” Ukraine prime minister Arseny Yatsenyuk warned, as Russian troops surrounded at least two military bases in Crimea and the country’s Naval commander defected to Moscow.

World leaders and the head of Nato echoed Kiev’s warning after pro-Russian forces took over government buildings and the two main airports in the region on the Black Sea where Russia has a naval base, heightening tensions.

Ukraine is fully mobilising its military and has called in its reservists to bases across the country, banned all military overflights on its territory and placed armed soldiers at all its airports.