“The Russians were in control of about 70% of the city, but have been forced back over the past two days,” Lugansk regional governor Sergiy Gaiday wrote on Telegram.

“The city is divided in two. They are afraid to move freely around the city.”

The region of Lugansk has been partly controlled by pro-Russian separatists since 2014.

Severodonetsk is the administrative capital of the Ukrainian part.

Gaiday said that Ukrainian forces had captured eight Russian prisoners.

He suggested that Russian general Aleksandr Dvornikov “has set himself a target of taking full control of Severodonetsk by June 10, or controlling the Lysychansk-Bakhmut road” which would open the way to Kramatorsk, the capital of the Donetsk region.

“All of the forces, all of the reserves are concentrating on these two tasks,” Gaiday said.

Yesterday, Russia’s army had claimed some Ukrainian military units were withdrawing from Severodonetsk but mayor Oleksandr Striuk said Ukrainian forces were fighting to retake the city.

“Our soldiers have managed to redeploy, build a line of defence,” he said in an interview broadcast on Telegram yesterrday.

“We are currently doing everything necessary to reestablish total control.”