More than 6,000 passengers were left stranded at Moscow's Domodedovo airport on Sunday after a heavy overnight snowfall caused cancellations, Russia's Aviation Committee (Rosaviatsia) said.

Some 70 flights were cancelled at Domodedovo airport, Russia's busiest, after two electricity substations were knocked out.

The power cut affected about 100,000 people in the region, the Moscow United Electric Grid Company said.

A spokesman for Rosaviatsia said power has not been fully restored yet but that the airport is "partially operational."

There is no rail service between central Moscow and the airport.

Further snowfalls in Moscow caused serious problems for motorists, as officials warn people against going outside.