About 10 people including the gunman have been killed at an adult education center in what Sweden’s prime minister called the country’s “worst mass shooting.”

Police said at least 10 people were killed at a school on Tuesday, in what has been described as the worst mass shooting in Sweden’s history. The suspected perpetrator also died.

Police investigating Sweden's worst mass shooting were still trying to establish a motive as to why a lone gunman opened fire at an education campus in the southern city of Orebro, killing 10 people.