Two people who were to swim in the Pite River at a campsite in Älvsbyn are missing.
The information we have is that two people have swum in the water and we do not know where they are now, says the police's press spokesperson Marie Andersson.
The alarm came at 11 am on Sunday.
The rescue service ended their operation at 4 pm, but the police continue to search for the missing persons with the help of divers.
Earlier, there was also an ambulance and a helicopter on site, but they have now left the campsite, writes Piteå-Tidningen.