Ukraine crisis: 'Thousands of Russians' fighting in east
28 August 2014 Last updated at 12:33 BST
A pro-Russian rebel leader in eastern Ukraine has said 3-4,000 Russian citizens are fighting in their ranks.
Alexander Zakharchenko, who is prime minister of the self-declared Donetsk People's Republic, said Russian citizens were coming to Ukraine to fight because they felt it was their duty.
Rebels captured the town of Novoazovsk and threatened to take the city of Mariupol, after opening a new front in the south-east.
There are suspicions that Russia wants to divert Ukrainian forces from the besieged cities of Donetsk and Luhansk, further north.
David Stern reports from Kiev.