Three people were killed in a blaze that broke out at a Russian hospital treating patients with Covid-19, authorities said, with one official suggesting a faulty ventilator was to blame.

Reuters reports the fire broke out at a hospital in the city of Ryazan, some 180 kilometres from Moscow, in a ward treating Covid-19 patients.

The region's governor, Nikolai Lyubimov, told state television that a ventilator in the ward had overheated and caught fire, the Interfax news agency reported.

Nurses attempted to extinguish the blaze, but were unsuccessful in doing so, with some of them sustaining severe burns, the governor said.