Russian soldiers storm a Ukrainian military air base in the small city of Belbek near Sevastopol (22 March 2014) Nearly all Ukrainian bases in Crimea are now under Russian control. Photo: BBC NEWS

Russian troops have seized most of Ukraine's bases in the peninsula, including the naval base at Feodosia.

Earlier this month, Russia annexed Crimea after a referendum which Ukraine and the West considered illegal.

The G7 group of industrialised countries is to consider a collective response to the crisis during talks in The Hague.

G7 leaders are meeting on the sidelines of a long-planned summit on global threats to nuclear security.

'Pressure and aggression'

"The national security and defence council has reached a decision, under instructions from the defence ministry, to conduct a redeployment of military units stationed in the Autonomous Republic of Crimea," interim President Turchynov said.

"The cabinet of ministers has instructions to resettle the families of soldiers as well as everyone else who today is forced to leave their homes under the pressure and aggression of the Russian army's occupying forces."

The announcement came shortly after Russian troops captured the naval base at Feodosia, the third such takeover in 48 hours.

Defence spokesman Vladislav Seleznyov said the Russians had attacked the base from two directions using armoured personnel carriers and stun grenades.

Feodosia was one of the last remaining bases under Kiev's control, but had been surrounded by Russian forces for some time, the BBC's Mark Lowen in Crimea said.

Two other military bases were stormed and seized on Friday.

Russian defence officials said earlier that the tricolour of Russia had been hoisted at 189 Ukrainian military units and facilities in Crimea.

The view in Kiev is one of deepening concern, says the BBC's David Stern in the Ukrainian capital.

The question now, he says, is how Ukraine and the West will respond, and what Russia's next move will be.

Nato's military commander in Europe warned on Sunday that Russian forces on Ukraine's eastern borders were capable of mounting an operation all the way to Moldova.

In other developments:

• Several parts of Crimea were hit by power cuts on Sunday evening, which officials blamed on technical problems

• There is still no confirmation of the whereabouts of Col Yuli Mamchur, the commander of Belbek base, which fell on Saturday. He was taken by Russian forces reportedly to a military prison. The interim Ukrainian president has demanded his immediate release

Moscow's annexation of Crimea on 16 March came after protesters overthrew pro-Kremlin President Viktor Yanukovych in February.

Russia said it had acted to protect its "compatriots" in Crimea from "fascists" moving in from mainland Ukraine.

The US and EU have responded with a series of sanctions targeting those individuals including senior officials whom they accuse of involvement in Crimea's annexation.