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 have said 11 people have been killed after a gunman opened fire at an adult education centre in Örebro, Sweden.Armed police were scrambled to Risbergska School at lunchtime on Tuesday as terrified students hid under their desks and barricaded themselves in classrooms.

The shooting is believed to have taken place at Campus Risbergska, which caters for students over the age of 20 in the town of Orebro.