The Kremlin on June 18 blamed a fresh surge in COVID-19 infections on "overwhelming nihilism" among Russians.
Meanwhile, Moscow Mayor Sergei Sobyanin announced an extension until June 29 of restrictions imposed earlier this week.
Kremlin spokesman Dmitry Peskov said Russia's vaccination campaign had clearly not been as effective as desired. He said President Vladimir Putin was closely monitoring the situation.
Sobyanin earlier announced the closure of Moscow's Euro 2020 fan zone and a ban on gatherings of more than 1,000 people.
"I didn't want to do this, but we have to," Sergei Sobyanin wrote on his website. "Starting today, we will limit mass events to a maximum of 1,000 people."
"We are temporarily stopping all mass entertainment events and we'll also have to close dance halls and fan zones," he wrote, referring to the Euro 2020 fan zone outside of the Luzhniki stadium in Moscow.
Peskov told reporters that "overwhelming nihilism, a low vaccination rate, and the deviousness of the infection itself" were the cause of Moscow's record surge in infections.
Peskov was echoing the opinion of Anna Popova, the head of Russia's health watchdog Rospotrebnadzor. On June 17, she also had blamed the spike in daily infections on Russians' disregard for preventative measures.
"[The infection growth] is linked to three reasons that are completely clear," she told Rossiya-1 TV. "The first is total nihilism for the measures that we used to protect ourselves from the coronavirus for a long time."
Sobyanin had said this week that the Russian capital was facing a new, more aggressive and infectious coronavirus variant.
Sobyanin this month ordered mandatory vaccinations for a number of service workers in the city and declared this week a nonworking week. Businesses will return to work on June 21.
On June 17, authorities in three other Russian regions -- the broader Moscow region, the Siberian region of Kemerovo, and the Far East region of Sakhalin -- said they planned to introduce the compulsory coronavirus vaccinations in the service sector, including in retail, education, and health care.
Critics of the requirement say there is no legal basis for companies to pressure staff to get shots in order to meet the decrees and avoid penalties.
Russia was among the first countries in the world to roll out a vaccination campaign, but there is widespread hesitancy to get a shot.
WATCH: Facing A COVID-19 Surge, Moscow Makes Vaccines Mandatory For Some Workers
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Facing A COVID-19 Surge, Moscow Makes Vaccines Mandatory For Some Workers
As of early June, only 12 percent of Russia’s 146-million population had received at least one dose.
Even in Moscow, only 15 percent of the city's population of 12 million has been vaccinated.
Prime Minister Mikhail Mishustin said on June 17 that the situation was "extremely difficult" and the country must “step up the vaccination pace."
"Experts speak of the emergence of new strains that not only spread rapidly, but also lead to serious complications," he said.
Authorities say the so-called delta variant that hit India hard and has since spread around the world is behind the rise of cases in Russia.
The delta variant is believed to be faster-spreading than other strains of the virus and there is some evidence to suggest it causes higher hospitalization rates.
Russia has reported almost 5.3 million confirmed virus cases and nearly 128,000 deaths, although real figures are believed to be much higher.