LUKA: Thirty-seven people were killed when a fire swept through a wooden psychiatric hospital in northwest Russia overnight Thursday, in the latest tragedy to hit the country's mental health institutions.

The fire was started by a patient who was either smoking or deliberately set fire to his bed at the hospital in the village of Luka, 220 kilometres (137 miles) southeast of Saint Petersburg, officials said.

The institution was made out of wood and officials said it had been previously warned by the judicial authorities to improve its fire security.

A criminal probe has been opened into suspected negligence.

"During a fire in the Oksochi psychiatric hospital 37 people died," regional investigators said in a statement, adding that 10 people have already been pulled from the debris.

"A 46-year-old nurse who was saving people perished in the fire," investigators added.

The fire, which broke out in the middle of the night, reduced the aged wooden building on the outskirts of the village to smouldering wreckage.

Rescue teams were combing through the debris, and bodies in black plastic bags were taken away from the scene.

Novgorod region governor Sergei Mitin told AFP at the scene that 23 people had been rescued.

Ilya Denisov, a representative of the emergencies ministry, did not rule out that more survivors could be found.

He said the firefighters were quick to react but that by the time they arrived the fire had consumed the entire building.

Local authorities said the hospital housed patients with grave psychological disorders, making evacuation even more complicated.

Lidiya Vasilyeva, 40, who lives near the hospital, said the fire broke out around 2:00 am.

"The fire spread very quickly," she said. "Many patients were pushed out of the windows, many did not want to come out or did not come out immediately, it was very scary."

She said it was difficult to pinpoint the cause of the blaze but suggested a patient might be at fault.

"In the summer they brought a patient here who they say was suffering from pyromania," she told AFP.

Investigators said they had opened a criminal probe into suspected negligence causing death.

"According to preliminary information, one of the patients set fire to himself and his bed," said the investigative committee, a Russian law enforcement agency that probes major cases.

Officials said concerns had already been aired about the state of the building, and Russian state television said the authorities had been planning to close down the hospital.

"This building had a weak resistance to fire. It was made of wood. The administration had been told by the legal authorities to remedy numerous violations in fire security by August 1," said the head of oversight at the emergencies ministry, Yuri Deshovykh.

"But this was not done," he was quoted as saying.

The Kremlin's human rights envoy, Vladimir Lukin, sounded the alarm over the state of psychiatric hospitals in the country, calling for a joint effort to improve oversight.

"The entire society, people should protect citizens who have found themselves in a unique, difficult situation when they cannot protect themselves," Lukin said on popular radio station Moscow Echo.

The fire was the latest tragedy to hit a medical institution in Russia, which struggles with outdated Soviet-era infrastructure and lax security procedures.

In April, a fire that ravaged a psychiatric hospital in the Moscow region killed 38 people, most of them patients engulfed by flames as they slept behind barred windows.

In 2006, a fire in a Moscow drug rehabilitation clinic killed 45 women, many of whom were trapped by metal bars on the windows that staff could not open.