Russian forces have been slowly advancing westwards following shelling and probing assaults towards the town of Siversk in Ukraine's Donetsk region from Lysychansk, Britain's defence ministry said on Friday.

"Bakhmut is likely to be the next objective, once Siversk is secured," the ministry tweeted in a regular bulletin. (Reporting by Ann Maria Shibu in Bengaluru; Editing by Jacqueline Wong)