MOSCOW/KYIV- Russian-backed separatists in eastern Ukraine said on Friday they planned to evacuate their breakaway region's residents to Russia, a stunning turn in a conflict the West believes Moscow could use to justify an invasion of Ukraine.

Announcing the move on social media, Denis Pushilin, head of the self-proclaimed Donetsk People's Republic, said Russia had agreed to provide accommodation for those who leave. Women, children and the elderly should be evacuated first.

There was no immediate commment from Russian officials or from Kyiv. Millions of civilians are believed to live in the two rebel-held regions of eastern Ukraine; most are Russian speakers and many have already been granted Russian citizenship.

The eastern Ukraine conflict zone saw the most intense artillery bombardment for years on Friday, with the Kyiv government and the separatists trading blame. Western countries have said they think the shelling, which began on Thursday and intesified in its second day, is part of a pretext to invade.

The United States said Russia - which says it has started drawing down troops near Ukraine this week - had done the opposite: ramping up the force menacing its neighbour to between 169,000 and 190,000 troops, from 100,000 at the end of January.

"This is the most significant military mobilisation in Europe since the Second World War," U.S. ambassador Michael Carpenter told a meeting at the Vienna-based Organization for Security and Cooperation in Europe.

A diplomatic source with years of direct experience of the conflict described shelling in eastern Ukraine as the most intense since major combat there ended with a 2015 ceasefire.

 

'THEY ARE SHOOTING'

Close to 600 explosions were recorded on Friday morning, 100 more than on Thursday, some involving 152 mm and 122 mm artillery and large mortars, the source said. At least four rounds had been fired from tanks.

"They are shooting - everyone and everything," said the source. "There's been nothing like this since 2014-15."

Other officials have disputed that characterisation, noting that there had been periods of deadly fighting during the ceasefire, and that there were no reports so far of deaths at the frontline this week.

Russia denies Western accusations it is planning an all-out invasion of Ukraine, a country of over 40 million people, in what would potentially be Europe's biggest war in generations.

Western countries have said this week that Russian troops are making the sort of preparations normally seen in the final days before an attack, which could come within days.

Moscow, for its part, said it was closely watching the escalation of shelling in eastern Ukraine, where government troops have faced Moscow-backed rebels since 2014. It described the situation as potentially very dangerous.

(Reporting by Reuters bureaux Writing by Peter Graff Editing by Gareth Jones)