[Jimbuna]

Ukraine has urged citizens living in Russia to leave the country immediately.

Up to three million Ukrainians are believed to live in Russia and many people have family in both countries.

A state of emergency is to be declared in Ukraine, lasting 30 days, the country's top security official says.

Ukraine is also conscripting reservists into the regular military as it braces for a possible invasion by its neighbour.

Western countries and their allies have imposed sanctions on Russian banks and MPs, as the crisis escalates.

But critics, among them the UK's Labour Party, say the measures so far are not strong enough.

It's not clear if any new Russian troops have yet been sent into the two regions, which are run by Moscow-backed separatists.