MOSCOW (Reuters) - The number of recorded coronavirus cases in Russia reached 658 on Wednesday, a day after the mayor of Moscow told President Vladimir Putin that the real scale of the problem in the Russian capital far exceeded official figures.

FILE PHOTO: A woman looks out of a window while having a meal inside a hospital for patients infected with coronavirus disease (COVID-19) on the outskirts of Moscow, Russia March 23, 2020. REUTERS/Maxim Shemetov/File Photo

The number of cases in Russia increased by 163 overnight, the biggest one day rise so far, the government’s official coronavirus website showed. Most cases, 410, were in Moscow.

Data showed that cases had been discovered in 55 different regions overall, that 29 people had recovered from the virus, and that nobody had died. A woman who tested positive for the virus died earlier this month, but authorities blamed a blood clot at the time.

The city of Moscow changed its coronavirus testing system this week, something likely to lead to more cases being recorded.

Samples were previously sent to a lab in Siberia for a second round of testing to confirm a positive result received during tests conducted in labs in the capital, the city’s coronavirus response headquarters said in a statement on Monday. That practice has now been discontinued.

Moscow Mayor Sergei Sobyanin, a close Putin ally, told the Russian leader on Tuesday that a serious situation was unfolding in the capital and that the real number of cases was unclear but was increasing quickly.

Testing for the virus was scarce, said Sobyanin, and many Muscovites returning from abroad were self-isolating at home or in holiday cottages in the countryside, and not being tested.

Reuters reported earlier this month that a reported sharp increase in pneumonia cases in Moscow and contradictory information around the issue was fuelling fears about the accuracy of official coronavirus data which remains much lower than many European countries.

Russia has taken a raft of measures to try to limit the spread of the virus, including partially closing its 4,300 km (2,670 mile) border with China and banning the entry of all foreign nationals.

The Russian government on Tuesday told regional authorities to close nightclubs and cinemas. Citizens aged over 65 have also been asked to remain at home to limit their exposure to the virus.