We received an alarm at 00.16 when a pilot in a Norwegian aircraft believed he saw drones during the approach to the airport, says Gisle Sveen, operational manager at the police in Norway, to the news agency NTB.
According to the alarm, it is about three to five drones, but the police have not yet been able to confirm that it was actually drones that were observed.
Several aircraft were either delayed or had to be redirected, according to the news agency.
At 01.30, the airport had returned to normal operations.
Air traffic was stopped about two weeks ago after an alarm about drone observations.
