"We do not yet know what is behind the act, but we know that the police are working very intensively. I would like to ask everyone to let the police and rescue services work undisturbed," writes Kristersson.
At least two boys have been seriously injured after the perpetrator entered the school, but much is still unclear about the incident. The suspect has been arrested by police.
The Social Democrats' party leader also comments on the incident:
"Terrible information from Fagersta. My thoughts go out to those affected and everyone affected. When violence takes place at a school, I know it affects everyone in our country. All of Sweden stands with Fagersta in this difficult time," she writes in a statement to TT.
Minister of Justice Gunnar Strömmer says in a written comment to TT that he has been informed of a "serious incident" in Fagersta.
"The police are on site and working very intensively on the incident. The government is in close contact with the police and is monitoring developments on an ongoing basis."
