The emergency services evacuated the children from the nursery school in Bredäng, a suburb in the south of Stockholm, after the fire started in the gym at Slättgårds school.
“Nobody was in the gym, as the children are not at school this week,” said Björn Engström at Stockholm police.
By mid-afternoon on Tuesday the fire had completely overwhelmed the 600 square metre gym. Large flames were coming out of the hall’s windows.
“We have 39 firemen at the scene. We’re starting to get some sort of control over it now,” said Pelle Rytterlund at Stockholm fire brigade at around 2pm. Firefighters expected it to take until at least 4pm to extinguish the main fire.
Two roads near the school have had to be closed in both directions.
It is so far unclear why the fire started.