Moscow authorities reimposed work-from-home restrictions Friday as the Russian capital posted a new daily record for Covid-19 deaths due to a surging outbreak of the Delta variant.

In a decree published on his website, the city's mayor Sergei Sobyanin ordered that businesses cut their number of in-office workers by 30 percent from June 28.

Vaccinated employees would be excluded, the decree said, adding that all workers aged over 65 as well as those with pre-existing conditions would have to work from home.

The new measures come as Russia has seen an explosion of new cases since mid-June driven by the highly infectious Delta variant first identified India. 

In Moscow, the epicentre of Russia's outbreak, the variant represents 90 percent of new infections, Sobyanin has said.

Authorities reported 20,393 infections across the country on Friday, including just under 8,000 in the capital. 

Moscow also recorded 98 coronavirus deaths, its highest one-day toll since the start of the pandemic.  

The Delta variant has been surging among a population that has largely rejected coronavirus vaccines, despite jabs having been available for free since early December.

As of Friday, just 21.2 million out of a population of about 146 million had received at least one dose of a vaccine, according to the Gogov website, which tallies Covid figures from the regions and the media.

With Russia's vaccination campaign faltering, Sobyanin earlier this month ordered some 60 percent of all service industry workers in Moscow -- just over two million people -- to be fully vaccinated by August 15. 

The head of health watchdog Rospotrebnadzor, Anna Popova, said Friday that 18 regions across Russia have now introduced some form of compulsory vaccination. 

Russia, with 132,064 coronavirus deaths officially recorded, is the hardest hit country in Europe.

Under a broader definition for deaths linked to Covid, statistics agency Rosstat at the end of April said that the country has seen at least 270,000 fatalitiess since the pandemic began.