Russia’s coronavirus outbreak is likely to be far larger than government data suggest, Moscow’s mayor has warned, as a surge in confirmed cases makes the country the world’s seventh most affected. The government said the official number of Covid-19 cases jumped by more than 10,000 on Sunday, a new record daily increase, and the largest outside the US. The figure underscores warnings from the Kremlin that the pandemic will continue to spread until at least mid-May.

But Sergei Sobyanin, Moscow’s mayor, said on Saturday that a new survey using improved testing methods suggested 2 per cent of the capital’s citizens were infected with coronavirus, equal to more than 250,000 people, or four times the number of officially confirmed cases in the city. “It is obvious that the threat is still growing,” Mr Sobyanin said in a statement posted on his personal website. “Once again I appeal to you, dear Muscovites, with a request to treat self-isolation measures as responsibly as possible.”

Russia on Sunday said almost 135,000 coronavirus cases had been recorded nationwide and close to 1,300 people had died of the virus. That lifts Russia above Turkey in the list of worst-affected countries, according to Johns Hopkins University data. Xi Jinping and Vladimir Putin are the big losers from this pandemic

While Russia reported far fewer cases of coronavirus in February and early March as the number of infections surged in other European countries, it has struggled to contain the outbreak over the past six weeks, with cases recorded across its vast territory. Unlike the European countries with more confirmed cases – Germany, Spain, France, Italy, and the UK –  the number of news cases recorded each day is still rising, and the Kremlin has warned that the outbreak may only begin to plateau by the middle of May.

President Vladimir Putin last week warned Russians in a national address that “the most intense stage in the fight against the epidemic” was still ahead.Mr Putin appointed a temporary replacement for prime minister Mikhail Mishustin on Thursday after the head of government said he had contracted the virus. The head of Rospotrebnadzor, Russia’s health watchdog on Sunday said that a national lockdown in place since late March could be extended beyond mid-May if citizens violated the rules during the annual May holidays that began this weekend.