SWEDEN’S worst mass shooting left at least 11 people dead, including the gunman, at an adult education centre west of Stockholm, officials said today.

They warned that the death toll could rise still higher.

The gunman’s motive, as well as the number of wounded, has yet to be determined as the Scandinavian nation — where gun violence at schools is very rare — came to terms with the attack.

Police said the carnage had made it difficult to count the number of dead.

The centre, called Campus Risbergska, on the outskirts of Orebo, around 125 miles west of Stockholm, offers primary and secondary educational classes for adults aged 20 and older, Swedish-language classes for immigrants, vocational training and programmes for people with learning disabilities.

Justice Minister Gunnar Strommer called the shooting “an event that shakes our entire society to its core.” 

The shooting started on Tuesday afternoon after many students had gone home following a national exam. Those who remained sheltered in nearby buildings, and other parts of the school were evacuated.

Roberto Eid Forest, head of the local police, told reporters that the suspected gunman was among the dead.

There were no warnings beforehand, and police believe the perpetrator acted alone.

Authorities haven’t said if the man was a student at the school, nor have they revealed a possible motive, but said there were no suspected connections to terrorism at this point.

Police raided the suspect’s home, but haven’t said if anything relevant was found.

“Today, we have witnessed brutal, deadly violence against completely innocent people,” Prime Minister Ulf Kristersson told reporters in Stockholm late on Tuesday. 

“This is the worst mass shooting in Swedish history. Many questions remain unanswered, and I cannot provide those answers either,” he said.

“But the time will come when we will know what happened, how it could occur, and what motives may have been behind it. Let us not speculate.”