The Stockholm police say they have taken four young people in for questioning, after an explosion at a high school school during a chemistry lesson.
Three teachers and 11 students were burned when a plastic bottle exploded and splashed them with corrosive fluid. The school, Kvarnbergsskolan in Huddinge, was evacuated of all 600 students.
Four people have been taken to the hospital.
A 13 year old witness says to news agency TT that a small plastic bottle flew into the school's central hall from an upper floor, and when a teacher came to pick up the bottle it exploded in her hand. The witness also says that the fumes from the chemicals made him cough blood.
Firefighter Katerina Lindén says to Radio Stockholm that they know that it was a small plastic bottle that contained an unknown fluid. And that they have sealed off the school for investigation. At the police Ulf Lindgren says that those injured were splashed with some kind of chemical.
Police are now investigating whether to arrest anyone for endangering the public.