The alarms came in on Monday afternoon.
Callers stated that something had been glimpsed in the airspace above Forsmark.
- We have received several calls with information that this is something that could be a drone in connection with the nuclear power plant, says Tobias Ahlén, press spokesperson at the police region in the middle.
Police patrols are on site and a helicopter has searched the area.
- We are investigating what it is, says Tobias Ahlén.
The text is updated.