Moscow’s heaviest snowfall in 100 years has left authorities battling to clear streets, and children told they could skip school.

City officials said 45cm of snow had fallen between Saturday and Monday morning, 20% more than the usual average for the whole month. 

Up to 20cm more was expected to fall on Monday, with temperatures forecast to fall to -17C.

 Mayor Sergei Sobyanin told journalists: "The snowfall of the century as it's been called has descended on Moscow" and resulted in "a huge amount of snow and thousands of toppled trees," RIA Novosti news agency reported.

"But nevertheless there has been no collapse or catastrophe," he stressed.

RIA Novosti dubbed the conditions a "snowy apocalypse". 

The defence ministry has sent soldiers to help clear snowdrifts on Moscow's streets as requested by city officials, it said in a statement.

"In the first five days of February the monthly average [snowfall] was reached," Nadezhda Tochenova, the deputy head of Russia's Hydrometcentre weather research centre told AFP. "That's an anomaly of course."

A depth of snow of 55cm was measured at one city weather station, Ms Tochenova said, while denying claims from the city hall that the snowfall was an all-time record.

Early in the morning, the city announced that children need not come to school -- although they would stay open.

"Due to the bad weather, we have announced that attending lessons in Moscow schools is optional," city hall's website said. 

Usually schools in Russia close only when temperatures fall extremely low. For example, in the Siberian city of Krasnoyarsk, older school children can only skip school if the temperature falls below -35C.

The emergency services also urged drivers to use public transport unless there was "extreme need" due to the risk of snowdrifts and black ice.

The mayor said that the sheer weight of snow had toppled 2,000 trees, and city authorities said more than 100 of those fell on cars. 

"One person died from a falling tree that hit an electric power line," Mr Sobyanin said on his personal website, adding the victim was a 27-year-old man.

One tree fell late Sunday on a metro train travelling on an overground track. Luckily it was not carrying passengers, the transportation network said.

The city sent its army of shovel-wielding snow clearers and hi-tech snow ploughs out in force, clearing 1.2 million cubic metres of snow in 24 hours, deputy mayor Pyotr Biryukov said.

The snow is taken to special snow melting stations where it is turned into water.

25 flights were delayed at Moscow's northern Sheremetyevo airport.

Aeroflot said it had also cancelled 25 flights to and from Sheremetyevo due to bad weather.

In a city well accustomed to wintry weather, the heavy snowfall did not affect central heating or power supplies and public transport was largely running.