A gunman opened fire at an adult education center in the Swedish city of Örebro on Tuesday, killing at least 10 people in what the country’s prime minister called the “worst mass shooting in Swedish history.

Swedish Prime Minister Ulf Kristersson described Tuesday’s shooting at an adult education center in Örebro (200 kilometers west of Stockholm), which left at least ten people dead, as the “worst” in the history of the Nordic country.

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.

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.

As many as 10 people have died in a shooting at a school in Sweden, police have confirmed. The deadly attack happened on Tuesday afternoon at Risbergska School, an adult education centre, in the city of Örebro, about 125 miles west of Stockholm.

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.”

Sweden’s worst mass shooting has left at least 11 people dead including the gunman and five seriously wounded at an adult education center

Officials in Sweden have vowed to determine why a man killed 10 people, and apparently himself, in an unprecedented attack that's shaken their "society to its core."

"It is a very painful day for all of Sweden," Prime Minister Ulf Kristersson said in a statement posted on social media.

A student at the education centre in central Sweden has recalled how she and others tried to help one of the victims of what would turn out to be the worst school shooting ever to happen in Sweden. "A guy next to me was shot in the shoulder.