North Stockholm police have reported that they fear that the pupils have sustained serious injuries.
“They were sitting with their backs to the window, and suddenly the window burst open and all three fell out,” Björn Engström at Stockholm police told news agency TT.
The three pupils, two boys and one girl and all reported to be between six and seven-years-old, fell ten metres to the ground and have sustained life-threatening injuries, according to the Aftonbladet newspaper.
The accident occurred at around 1pm on Monday and the three children are now being cared for at Astrid Lindgren’s Children’s Hospital in Solna.
It remains unclear as to the how the window could suddenly open.
“That’s something the technical investigation will show. The school has, or will, also contact the Swedish Work Environment Authority (Arbetsmiljöverket).
The school has appointed a crisis group to help pupils and staff deal with the shock.
“Several staff from Järfalla county council are on their way to the school to see what needs to be done,” Greger Ekström at the council to news agency TT.
Among the council staff are the county’s head of health and safety as well as several who work with schools issues.