All air traffic at Arlanda was halted on Monday night after several drones were sighted near the airport from the control tower.

"There were four of varying sizes," says Cecilia Bengtström, duty officer at the Swedish Civil Aviation Administration's press office.

Around five aeroplanes had to be rerouted to Nyköping and Gothenburg respectively due to the stop, Swedavia's press service informs TT.

At around 03:30, the decision was made to resume traffic again, according to Cecilia Bengtström.

The police are investigating the case as airport sabotage and a breach of the protection act.

– We have both been in contact and collaborated with other authorities, and the matter is being assessed as a police matter, at least at present, says Daniel Wikdahl, press spokesperson for the police.

He does not want to go into further details, citing that it is an ongoing preliminary investigation.

No person has been arrested.

Source:TT-Aftonbladet.se