More than 70 firefighters and 20 fire trucks were working at the site, emergency services say, adding that their work was hampered due to the design of the building.

Hundreds of mainly Western companies have announced the suspension of their activities or their departure from Russia after President Vladimir Putin sent troops to Ukraine on Feb 24.

The Russian defence ministry made the assertion after Ukrainian President Volodymyr Zelensky demanded tough new sanctions over killings in the town of Bucha that have prompted international condemnation.

Moscow had previously admitted to losses but without giving any numbers.

US officials warned the risk of a Russian invasion remained high and that Russia may attempt to fabricate a pretext for a conflict, despite Moscow saying it was moving some of its troops away from the border.

These are the first Covid-19 restrictions since the summer, as Russia registers a new record of 1,015 daily deaths.

A government tally showed 815 fatalities over the past 24 hours and 22,277 new cases.

Although free jabs have been available since early December, only around 15% of Russia's population have received at least one dose.

More than 50,000 new infections have been recorded in the Russian capital, the epicentre of the country's outbreak, over the past two weeks.

From the very beginning Russia has refused to condemn the coup.

The highly infectious Delta variant has been blamed for nearly 90% of new cases.

Over 9,000 new cases were recorded, up from 3,000 two weeks ago.