Police in Sweden said Tuesday that at least five people were shot at a school in the city of Orebro, which The Associated Press said was an adult education center. The police said they did not have information about the condition of the victims, and they warned “the danger is not over” as their operation was still underway.

Sweden’s TT news agency, citing anonymous sources, said the shooter had died of a self-inflicted gunshot wound sustained at the Campus Risbergska school, which, according to its website, is for students over the age of 20. The Reuters news agency said the adult education center is on campus that includes children’s schools.

The Swedish national police did not confirm that information, but said about two hours after their initial message regarding the incident that the shooter was believed to be among those transported to a local hospital. The police did not confirm reports by Swedish media that several people had been killed, but a statement attributed to National Police Chief Petra Lundh said, “Our thoughts go out to the victims and their families.”

“A major operation is currently underway at a school in Västhaga, Orebro,” the police said in a statement posted online, urging members of the public “to stay away from the Västhaga area” or, if not possible, to remain inside their homes.

“The operation concerns threats of deadly violence,” the police said. 

“The extent of the injuries is unclear,” the police said, adding a reference to charges of “attempted murder, arson and aggravated weapons offense,” but not confirming whether any suspect or suspects were in custody.

Sweden’s laws on firearm ownership are strict, with “the right to possess weapons, even for protection purposes,” requiring a license granted only with explicit permission from the police force, which must be applied for in advance of any intended purchase. A licensed gun owner must carry the document with them at all times when in possession of a weapon, and the law covers not only firearms but weapons that fire or deploy tear gas.