The Kremlin on Friday blamed a surge in COVID-19 cases on reluctance to get vaccinated due to "nihilism" after a record 9,000 new infections in Moscow fanned fears of a third wave and forced Russia's capital to close its Euro fan zone and extend other curbs.

Some 9,056 new cases were recorded in the megapolis of over 12 million in the past 24 hours, up from 3,000 two weeks ago and a new daily record since the COVID-19 pandemic began in early 2020, according to official statistics.

Moscow Mayor Sergei Sobyanin extended restrictions he had imposed earlier, which include a ban on public events with more than 1,000 people, an 11 p.m. closing time for cafes and restaurants, and the closure of fan zones set up for the European soccer championship. Sobyanin said earlier this week that Moscow was facing a new, more aggressive and infectious coronavirus variant, and that the situation in the city was deteriorating rapidly.

"I didn't want to do this, but we have to," Sobyanin wrote on his website, according to remarks carried by Agence France-Presse (AFP). "Starting today, we will limit mass events to a maximum of 1,000 people."

Kremlin spokesperson Dmitry Peskov said President Vladimir Putin was monitoring the situation closely. Asked to explain the surge in cases Peskov blamed the virus' "cunning nature," a reference to its mutations, as well as "total nihilism, and the low vaccination level."

At a briefing, he rejected the idea, posited by some critics, that Russians were reluctant to have vaccinations because they distrusted the authorities, as Reuters reported. As of June 2, the most recent tally available, only 18 million Russians had received at least one dose of vaccine so far: at one-eighth of the population, that is far less than most Western countries. Moscow authorities this week ordered all workers with public-facing roles to have a vaccination.

Sobyanin said on Friday he expected the city government to start the inoculation of migrant workers with Sputnik Light – a single dose of the Sputnik V vaccine – early next month.

But he also said it was "vitally important" to start administering further booster doses – in effect, the third dose. He said he himself had just received a top-up, after being fully vaccinated two doses a year ago. He said the third doses being offered were a repeat of the first dose of the two-shot Sputnik V vaccine.

Several Russian officials and members of the business elite, as well as some members of the public, have already been securing third and fourth doses of Sputnik V, Reuters reported in April.

The question of how long a vaccine offers protection against COVID-19 will be vital as countries gauge when or whether revaccination will be needed, and Russia's findings will be closely watched elsewhere.

Over the past week, the mayor has introduced a series of new restrictions in an effort to contain the wave of infections, including declaring a "work-free" week, closing venues, and ordering mandatory vaccinations of people working in the service industry in the city. Also on Friday, Sobyanin extended until June 29 several measures that were announced last weekend, like the closure of food halls in malls, zoos, playgrounds, and the closure of bars and restaurants between 11 p.m. and 6 a.m.

Russia's second city of Saint Petersburg, the country's worst COVID-19 hotspot after Moscow, is hosting seven Euro 2020 matches – including a quarter-final – and is expected to see thousands of football fans from Europe. On Monday, Saint Petersburg also announced a tightening of restrictions, including no food sales in its fan zones.

Russia overtook Britain on Thursday as the European country to record the most COVID-19 deaths with 127,992. However, the Rosstat statistics agency, which uses a broader clinical definition of fatalities linked to COVID-19, says at least 270,000 Russians have died from coronavirus.