A fire killed 37 people in a Russian psychiatric hospital on Friday, the second deadly blaze at such a facility this year, heightening concerns about Russia's treatment of the mentally ill and other vulnerable wards of the state.

Fires have frequently claimed high tolls among residents of state institutions such as hospitals, schools and homes for the handicapped in Russian the past decade, raising questions about safety standards.

Russia is also dogged by transport and industrial accidents, and Kremlin critics point to a culture of negligence and avoiding responsibility they say has been bred by President Vladimir Putin's top-down ruling style during more than 13 years in power.

The pre-dawn fire razed a dilapidated ward for severely ill male patients at the hospital in a provincial village north of Moscow, apparently killing some while under sedation as fog slowed firefighters travelling from 45 km (28 miles) away.

Emergency and law enforcement authorities had recently sought to have the run-down wood, brick and concrete building condemned as unfit for use, a senior official said. Federal investigators began a criminal inquiry into suspected lethal negligence.

State television showed firefighters spraying water on the smoking, blackened ruins of the ward at the hospital - footage that has become grimly familiar after fires at facilities including mental hospital where 38 people died in April.

A female orderly died while trying to save patients at the hospital in the village of Luka, which is in Novgorod province between Moscow and St Petersburg, the regional branch of the federal Investigative Committee said in a statement.

It said 37 people were killed, and the Emergency Situations Ministry said 29 bodies had been recovered by Friday afternoon.

"Psychiatric hospitals are the worst of all," said Yuri Savenko, president of the Independent Psychiatric Association of Russia. "Their condition is pathetic. It's inevitable that such things will occur increasingly often."

More than 20 patients were evacuated after the fire broke out shortly before 3 a.m. (2300 GMT on Thursday). Official initially said some others may have escaped on their own, but none had been found hours later by police combing the area.

The fire left little but the concrete foundation of the single-story building standing.