At least 11 people have been killed by falling trees and debris from buildings as a storm swept through Moscow on Monday, the national Investigation Committee said.
A further 69 people are reported to have been injured.
Moscow mayor Sergei Sobyanin said on his Twitter account that more than 40 people had asked for medical assistance.
Hundreds of trees were toppled, as meteorologists reported winds of up to 50 mph.
Cars were crushed and roads blocked by trees brought down by the storm.
It is believed to be the most serious storm to hit Moscow in more than 100 years.
“The hurricane was unprecedented for Moscow,” TASS news agency quoted him as saying.
News agencies reported falling trees had blocked roads and metro railways.
An elderly man was killed while waiting at a bus stop and two more died when a tree fell onto their summer house.
Moscow is usually spared such extreme weather, though high winds are not unusual in the region in the summer months.
The death toll was the highest due to storms in the capital in a single day for almost 20 years. Between eight and 11 people died in storm in the capital in 1998.