Valentyn Reznichenko

Ukraine said Russia had unleashed a fresh barrage of missiles Saturday, killing at least 14 people, as Britain became the first Western country to offer it the heavy tanks it has long been seeking.

The British move drew a swift reaction from Moscow, which warned it would only "intensify" the conflict.

Fears about the potential for a radiation leak at Europe's largest nuclear power plant persisted Saturday as both sides traded blame for nearby shelling. Ukraine said Russian forces fired on areas just across the river from the plant and Russia claimed Ukrainian shells hit a building where nuclear fuel is stored.

At least seven civilians were killed in a shelling of the center of Kharkov on Thursday, local Ukrainian officials said. The Russian army also attacked more than 40 cities in Donbas, the Ukrainian army claims.

Dnipropetrovsk Governor Ihor Kolomoisky has resigned as the governor of Dnipropetrovsk after a row with the government over the future of propertu where he is one of the shareholders.

Ukraine President Petro Poroshenko has accepted his resignation and has appointed Valentyn Reznichenko to take over ad interim.