Thirty-eight people, mostly psychiatric patients, were killed in a fire that raged Friday at a psychiatric hospital in the Moscow region, trapping the inmates inside behind barred windows.
The deadly blaze raised new questions about security standards at Russia's medical institutions, in particular psychiatric hospitals, after a string of fires in the last years.
The fire broke out on the roof and spread rapidly throughout the hospital in the small town of Ramensky around 40 kilometres (25 miles) outside Moscow, the health ministry said.
"According to preliminary reports, 38 people were killed, including two medical staff," said ministry spokesman Oleg Salagai, cited by the RIA Novosti news agency.
The emergency situations ministry said in a statement that 41 people were in the building at the time. It listed those missing as two female members of staff and 36 patients.
"Twelve bodies have been found" so far, it said as firefighters searched through the rubble after more than 100 battled to extinguish the fire.
Russia's Investigative Committee said in a statement it had opened a criminal probe into failure to observe fire security regulations, causing multiple death.
Two patients and one member of medical staff escaped the fire in the one-storey brick building which had a partly wooden roof, the emergency situations ministry said.
Most of the patients apparently died in their sleep from inhaling fumes, but they would have been unable to escape from the fire which raged through the building with bars on the windows, Rossiya 24 television reported, citing law enforcement officials.
The patients slept soundly as they had taken medication in the evening, the ITAR-TASS news agency reported, citing a spokesman for the rescue operation.
The smoke alarms did activate in the hospital and woke a nurse who managed to save two patients, the rescue operation spokesman said.
"When the nurse came out into the corridor, the fire was burning and the flames were spreading quickly. She managed to bring out only two patients: a woman and a young man," the spokesman said.
Channel One television said that the emergency services had been slow to react, with the fire brigade taking an hour to get there.
"There were bars on all the windows of the hospital. Most of those killed died in their beds and it appears that they were not even able to save themselves," a security source told the Interfax news agency.
Moscow region governor Andrei Vorobyev, a protege of President Vladimir Putin from the ruling United Russia party, was already at the scene, officials said.
The Moscow region announced a day of mourning to be held on Saturday.
The fire was the latest tragedy to hit a medical institution in Russia which still suffers from outdated Soviet-era infrastructure.
May 2007 two died and 12 injured in a village psychiatric hospital in Russia's southern Rostov region.
In December 2006, a fire in a Moscow drug rehabilitation clinic killed 45 women. Many of the victims were trapped by metal bars on the windows that staff could not open and an emergency exit was boarded up, officials said.
In March 2006, a fire in a nursing home in southern Russia killed 63, also due to violations of fire safety regulations and the lack of a nearby firefighting station.