Vladimir Putin has fired intercontinental ballistic missiles that some Russians mistook for an alien invasion during a snap drill of the country's nuclear forces.

The president carried out the launch of four ballistic missiles, his spokesman said on Friday, as part of wide-ranging exercises to test the coordination of Russia's nuclear triad of ground-based missiles, submarines and strategic aviation.

A video released by the defence ministry showed a mobile launcher firing a Topol intercontinental missile from the Plesetsk cosmodrome in northwestern Russia on Thursday night. The missile traversed almost the entire country to strike its target at a testing range in Kamchatka in the far east.