Russia is likely to reinforce its operations in the industrial Donbas region once they secure the city of Mariupol, British military intelligence said early on Friday.

As many as 1,700 soldiers are likely to have surrendered at the Azovstal steel factory in Mariupol, the report added.

Moscow also said on Thursday that 1,730 Ukrainian fighters had surrendered from the steel factory so far, including 771 in the past 24 hours. Ukrainian officials, who have sought a prisoner swap, had declined to comment, saying it could endanger rescue efforts.

(Reporting by Jaiveer Singh Shekhawat in Bengaluru; Editing by Christian Schmollinger)