The state Investigative Committee said the suspected crimes were negligence, and causing death by negligence. It did not say who was under investigation.

Investigators have seized medical records at the hospital in the city of Novokuznetsk and are conducting forensic tests to determine the cause of the deaths, it said. Staff were also being questioned about the actions they had taken, or failed to take.

The regional governor said the hospital’s main doctor had been removed from his post.

The hospital said on its website that it had suspended admissions because of an excess of respiratory infections, and was carrying out quarantine measures.