The Moscow mayor on Friday sounded the alarm over a spike in coronavirus cases saying Covid-19 was becoming more difficult to treat as city authorities posted the highest number of daily infections since January.
"We expected that the spring pandemic peak would fall on April-May just like last year," mayor Sergei Sobyanin said in televised remarks.
"But now we're seeing that it has shifted towards June-July."
Sobyanin, a close ally of President Vladimir Putin, estimated that around half of Moscow residents had by now some level of immunity against the virus.
"At the same time we are seeing just how aggressive Covid is," he said, stressing that it was becoming more difficult to treat it.
"Quite a lot of Muscovites are in intensive care on ventilators," he said. "The danger is real."
Health authorities on Friday reported 5,853 new cases of coronavirus in Moscow, a record since mid-January.
Russia has been among the countries hardest hit by Covid-19.
Russian health officials have registered more than five million coronavirus cases and more than 125,000 deaths but some experts say officials vastly under report fatalities.
The country has lifted nearly all virus-related restrictions and many Russians are refusing to wear masks on public transport and in other public places.
Russia registered Sputnik V, the world's first coronavirus vaccine, in August 2020, but authorities have struggled to ramp up vaccination efforts.