Police have confirmed that 11 people have now died following a mass shooting at an adult education school in Sweden and the number of injured is currently unclear.

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.”

Swedish police on Thursday described Tuesday’s school shooting as a “hellish” event that left 11 people dead, confirming that the suspected perpetrator was found dead with three licensed firearms in his possession.

The Swedish police reported that the alleged perpetrator of the shooting in Orebro possessed a permit for four firearms. Three of these were found on him, along with a large quantity of unused ammunition.

Witnesses who survived Sweden’s worst mass shooting have described horror and panic that gripped an adult education center west of Stockholm as the gunman killed at least 10 people.