This is a GlobalEye jet. Stock image.
The airplane took off from Linköping Airport at 08:30 on Wednesday. It was a Saab plane of the Bombardier Global Express model, also known as a GlobalEye plane, which Saab themselves describe as a "surveillance and command aircraft". It can be used for monitoring airspace, sea, and land.
About an hour after the plane had taken off, it was above Bjurträsk. The pilot then started flying back and forth to the Gulf of Bothnia in straight lines. At 12:20, the plane turned south again.
Readers reacted to the strange route and the fact that the plane flew at a high altitude - 28,000 feet. Data from flight tracking service Flightradar24 shows that the same plane has made similar flights before.
The news site The Barents Observer noted in early August that a Swedish military plane had made a very similar flight over Finnish airspace near Russia. That time, it was likely an intelligence mission, according to Norwegian defense expert Per Erik Solli.
Here is what he says about Wednesday's flight over Skellefteå:
– My assessment is that this is a routine mission. The plane has a radar that can see other planes, helicopters and drones. It looks like it has taken part in an exercise or a radar test.
Mattias Rådström, press officer at Saab, wants to keep the flight under wraps.
– We regularly conduct test flights with our various aircraft. However, we do not usually comment on what these tests actually consist of, he writes in an e-mail to Norran.