Aeroflot Airlines will adjust the schedule of several flights due to the morning restrictions imposed on the St. Petersburg-based Pulkovo airport, the airline said in a statement.

"In accordance with the information of the State Committee on ATM (air traffic management - TASS) on the restriction of the use of the airspace of St. Petersburg, Aeroflot is adjusting the flight schedule," the airline said.

In particular, the plane on the Moscow-Kaliningrad flight returned to the Sheremetyevo airport and will be operated later, several flights from Moscow to St. Petersburg and back have been canceled, they will later be operated by a larger capacity aircraft.

Earlier on Tuesday, a source familiar with the telegram of Russia’s Federal Agency for Air Transport (Rosaviatsiya) told TASS that airspace within a radius of 200 km around St. Petersburg's Pulkovo Airport is closed until 13:20 Moscow time.

The press service of the administration of St. Petersburg’s governor reported on its Telegram channel that the Pulkovo airport had announced a flight delay until 12:00 noon. The restrictions were lifted around 11:40 Moscow time. According to the Russian Defense Ministry, the duty forces of the Western zone of responsibility for air defense conducted a training session on interaction with civilian air traffic control authorities, emergency services and law enforcement agencies.