Approximately ten planes have been unable to land at St. Petersburg’s Pulkovo Airport due to security restrictions, an airport official said.

"For the time being, approximately ten flights are in the waiting zone," the source said.

The flights are from Chelyabinsk, Novosibirsk, Omsk, Ufa, Barnaul, Urgench, and Yekaterinburg.

Earlier, the Federal Agency for Air Transport said temporary restrictions had been imposed on Pulkovo Airport operations to ensure the safety of flights. Also, temporary restrictions on the use of airspace, imposed in the Leningrad Region, affected flights to and from Russia’s Baltic exclave of Kaliningrad.