At least 37 people have died in a fire at a Russian psychiatric hospital.

It was the second deadly blaze at a psychiatric hospital in Russia this year and is likely to prompt criticism of the state over its treatment of the mentally ill and other vulnerable citizens.

Emergency authorities had recently sought to have the building condemned as unfit for use, a senior official said.

The federal Investigative committee said an orderly died while trying to save patents at the hospital in the town of Luka in Novgorod.

The fire gutted a single-storey building housing male patients at the hospital.

There were about 60 people in the building, most of them patients, when the fire broke out.

Officials said more than 20 patients were evacuated from the hospital.

In April, a fire at a psychiatric hospital outside Moscow killed 38 people.

Investigators suspect the blaze was caused by a patient setting a bed on fire, Interfax news agency reported, but regional governor Sergei Mitin said it might have been accidental.

Emergency officials and prosecutors had sought to have the building condemned as unsafe, but a court instead ordered management to correct unspecified flaws by August 2014, the head of safety oversight for the Emergencies Ministry said.