MOSCOW (Reuters) - Russian President Vladimir Putin replaced the head of a remote northern region on Thursday soon after a preliminary investigation was launched to check if more than 50 people in a local hospital had been infected by a doctor.

Russia’s Komi republic, 1,000 km (620 miles) northeast of Moscow, has reported 56 cases of the virus, more than any other region outside Moscow, its surrounding region and St. Petersburg.

Fifty-five of those cases were related to a single hospital in the district of Ezhva in Komi’s regional capital, Syktyvkar, according to a statement by the regional administration.

Several hours after a statement that an investigation had begun, the Kremlin published a presidential decree saying that Putin accepted the resignation of Komi Republic Governor Sergei Gaplikov and appointed Deputy Health Minister Vladimir Uiba as temporary head of the region.

A coronavirus outbreak could be difficult to control in a region with a less well equipped health service than western Russia.

Russian media have reported that a surgeon could have been the source of the infection and the Investigative Committee that handles major crimes said on Thursday it was investigating.

“Preliminary checks were arranged following media reports that one of the medical workers of Ezhva’s district hospital could have infected a large number of people,” the regional branch of the Investigative Committee said in the statement.

Russia has reported 3,548 coronavirus cases, 80% of which are in Moscow, its suburbs and St. Petersburg, the most populated areas that have access to more advanced healthcare than the rest of the country.

The checks could take up to 30 days, Svetlana Korovchenko, a spokeswoman for the local investigative committee said.

“I think healthcare infrastructure in Komi is absolutely unprepared for an explosive outbreak of COVID-19,” said Ernest Mezak, a lawyer at the Public Verdict human rights group who is conducting his own investigation into the outbreak.

“Neither officials nor regular people were taking COVID-19 as a serious threat in Syktyvkar just a week ago.”

Last week Russia opened a criminal investigation into a senior infections specialist in the southern city of Stavropol who failed to self-isolate after a trip to Spain and allegedly infected several people.