Yahoo TV

STORY: Russian troops have entered the outskirts of the Ukrainian city of Sievierodonetsk, according to the regional governor, who described fierce fighting on Monday over the ruins of a city that has become the focus of Moscow's offensive.

Russia has concentrated its firepower on the last major population centre still held by Ukrainian forces in the eastern Luhansk province, in a push to achieve one of President Vladimir Putin's stated objectives after three months of war.

Incessant shelling has left Ukrainian forces defending ruins in Sievierodonetsk, but their refusal to withdraw has slowed the wider Russian offensive across the Donbas region, large parts of which are already controlled by Moscow-backed separatists.