The fire is now 25 percent contained and the cause hasn't been determined, though investigators are looking into whether it was lightning, an accident orarson.
The cause of the blaze, which broke out around 2 a.m. at Psychiatric Hospital No. 14 in Ramensky, about 80 miles north of Moscow, had not been determined and authorities were looking at the possibility of an electrical malfunction orarson and had opened a criminal investigation, Russia's Investigative Committee said.