Moscow Mayor Sergei Sobyanin on Friday ordered the elderly to stay at home and recommended employers allow home working after the Russian capital saw a sharp rise in virus cases.

Sobyanin's message came after virus figures that had remained steady for several months climbed steeply in recent days in Russia, the world's fourth most affected country, and particularly in Moscow, where current case numbers are the highest since late June.

Sobyanin said Muscovites over 65 years old should stay at home from Monday and shop rarely, while walks outside remain unrestricted.

At the beginning of the virus lockdown, Sobyanin brought in harsh measures including cancelling seniors' free travel passes.

"Unfortunately we see a significant increase in the number of confirmed cases in Moscow in recent days," Sobyanin said in his official blog.

New coronavirus cases in Moscow on Thursday reached their highest level since June 23, at 1,050, and Sobyanin said there had a been a "serious" increase in hospital admissions.

On Friday, he warned that simultaneously catching the common cold and the virus as winter approaches was particularly dangerous for elderly people and those with chronic illnesses.

"So from September 28, we are asking you to stay at home," he said.

The mayor's decree presents this as a compulsory rule, with exceptions for medical care, shopping, walking dogs and commuting to work.

The number of virus cases has climbed steeply in recent days in Russia, the world's fourth most affected country, and particularly in Moscow
The number of virus cases has climbed steeply in recent days in Russia, the world's fourth most affected country, and particularly in Moscow AFP / Yuri KADOBNOV

Sobyanin said those in the risk groups should work from home or take vacation if possible.

He also told company heads: "I firmly ask and recommend you to move as many of your staff as possible to home-working."

Employers should offer virus testing and temperature checks, he said.

Warning the virus is "not conquered yet," he called for Moscow residents to wear face masks and gloves on public transport and in shops, a rule already in place but widely flouted.

At the peak of lockdown Sobyanin only allowed people to go to their nearest shop or walk a dog, while those using public transport or cars needed electronic passes.

"We all really don't want to go back to he harsh restrictions of spring," Sobyanin said. "I hope we can avoid this."

Russia has confirmed 1,128,836 coronavirus cases and almost 20,000 deaths.

It has boasted of creating the world's first approved coronavirus vaccine, Sputnik V, although it is still undergoing clinical trials.

Sobyanin is among high-profile officials to have got inoculated.