Fighting raged in eastern Ukraine yesterday as pro-Russian separatists sought to tighten the circle around government forces clinging on to a rail centre, with 15 Ukrainian soldiers killed in 24 hours.

Defence Minister Stepan Poltorak said separatists were keeping up intense pressure on Debaltseve, a major rail and road junction north-east of the big city of Donetsk, as well as on the neighbouring town of Vuhlehirsk.

The rebels were also continuing to threaten Mariupol, a town of half a million in the south-east of the country on the coast of Sea of Azov, Lysenko said.