"Ten people died. They all got poisoned by products of combustion," Tass News Agency quoted the official as saying.
Firefighters received a signal about a fire in the hospice for the elderly, which is located in Krasnogorsk District in Moscow Oblast, at 11:59 p.m. local time (2059 GMT), and their first units rushed to the scene in 12 minutes.
"The fire was completely extinguished at 1:09 a.m. (2209 GMT)," the official said. The fire area was 15 square meters.
At the time of the incident, 37 people were in the hospice, including eight staff members, according to the Tass report.
Preliminary reports said the fire was caused by an explosion of fuel vapor in a boiler room, and the building where the hospice is located is said to be unsuitable for use.
A criminal case has been initiated.