Russia's defence ministry said it had carried out air defence drills involving interceptor jets after St. Petersburg's Pulkovo Airport was forced to suspend all flights on Tuesday for an hour.
The government of Russia's second city announced the closure on its official Telegram channel without providing a reason for the suspension, as unconfirmed media reports said an unidentified object, such as a drone, had been spotted in the area.
City officials said later on Tuesday that flights had resumed and that a temporary airspace ban within a 200-kilometre (124-mile) radius of Pulkovo had been lifted by 1200 local time (0900 GMT).
