Flights from cities in southern Russia near Ukraine were cancelled Thursday after President Vladimir Putin announced his army had begun a military operation in the country.

A man crosses the snow-covered frozen Moskva River with the North River Terminal on background in Moscow on January 1, 2022. (Photo: AFP)

Flights from 11 airports in southern Russia and one airport in Moscow-annexed Crimea were cancelled, Russia's main aviation authority Rosaviatsia said in a statement.

These include large cities such as Sochi, Krasnodar and Anapa. It said the restrictions will be in place until March 2.

"The aviation authorities of Russia strongly recommend that passengers on the next flights and those who meet them do not go to the airport," the statement read.