Russia destroys bridge near Ukraine's besieged Severodonetsk, cutting off a key escape route

Russian forces have blown up a bridge linking the embattled Ukrainian city of Severodonetsk to another city across the river, cutting off a possible evacuation route for civilians, local officials said on Sunday.

Severodonetsk has become the epicentre of the battle for control over Ukraine's eastern region of Donbas. Parts of the city have been pulverized in some of the bloodiest fighting since the Kremlin unleashed its invasion on Feb. 24.

Ukrainian and Russian forces were still engaged in street by-street fighting there on Sunday, said the governor of Luhansk province, Serhii Haidai.

Russian forces have taken most of the city, but Ukrainian troops remain in control of an industrial area and chemical plant where hundreds of civilians are sheltering.

But the Russians had destroyed a bridge over the Siverskyi Donets River linking Severodonetsk with its twin city of Lysychansk, Haidai said.

That leaves just one of three bridges still standing and reduces the number of routes that could be used to evacuate civilians or for Ukrainian troops to withdraw to positions on the western side of the river.

In Lysychansk itself, Russian shelling killed one woman and destroyed four houses and a shopping centre, Haidai said.

The head of the Severodonetsk administration said a little more than a third of the city remained under the control of Ukrainian forces and about two-thirds were in Russian hands.

"Our [forces] are holding the defensive line strongly," Oleksandr Stryuk told national TV.

After being forced to scale back its initial campaign goals following its invasion of Ukraine, Moscow has turned its attention to expanding control in the Donbas, where pro-Russian separatists have held a swath of territory since 2014.

Severodonetsk is the last city in Donbas's Luhansk province still held by Ukraine, and its loss would be a significant strategic blow. Victory for the Russians would move them a big step closer to one of Russian President Vladimir Putin's stated goals in what he calls a "special military operation."

Elsewhere, Russian cruise missiles destroyed a large depot containing U.S. and European weapons in western Ukraine's Ternopil region, Russia's Interfax agency reported.

Ternopil's governor said rockets fired from the Black Sea at the city of Chortkiv had partly destroyed a military facility and injured 22 people. A local official said there were no weapons stored there.

Reuters could not independently confirm the differing accounts.