Around 10 people were killed in a school shooting in Örebro. The damage at the crime scene was so extensive that investigators were unable to be more definitive, said Roberto Eid Forest, head of the local police.

Officials in Sweden have vowed to determine why a man killed 10 people, and apparently himself, in an unprecedented attack that's shaken their "society to its core."

The shooting occurred at a center for adult education in the city of Orebro. The suspect is believed to be among the dead, officials said.