During the night leading up to Monday, four drones of varying sizes flew near Arlanda Airport. On Monday evening, a new alarm about drones was raised.
It is not self-evident that there is a direct connection between the events, according to Hans Liwång, who is a professor at the Defence University and a lecturer in military technology. The second event could have been inspired by the uproar that followed the first.
There are some indications that the event on Monday night had the purpose of testing Arlanda's preparedness against that type of event, says Liwång, and mentions that it appears to have been more planned and required greater resources.
Arlanda has detected and acted, and taken the safe option in the face of uncertainty during the events, assesses Liwång.
He sees a broad spectrum of individuals or groups that could be behind it.
We have seen people with a more hobby-like purpose mapping Swedish protected objects.
It could also be instigated in some way by a foreign power.
One could have placed someone in Sweden to do this with the purpose of seeing what happens, says Hans Liwång.
