One person died and three were wounded after a sword-wielding attacker entered a high school in the town of Fagersta in central Sweden Friday, police said, adding the suspect had been arrested.

Local police chief Tommy Alriksson told journalists that one person had been found dead after police entered the school, having shot and arrested the assailant.

"Our current assessment of injuries is that there are three wounded people and one deceased," Alriksson told journalists, adding that two had been seriously wounded and a third had lighter injuries.

Alriksson said the arrested suspect was an 18-year-old man. Police were working on establishing a motive, but that they had no reason to believe there were multiple perpetrators, he added.

"It is a very serious and deeply shocking incident," Fagersta mayor Asa-Marta Sjostrom told reporters alongside Alriksson.

Regional healthcare director Jonas Cederberg told AFP earlier that two "seriously wounded" people had been admitted to hospital.

The two were boys between the ages of 12 and 17, and one of them was in emergency surgery though both were in a stable condition, the healthcare authority said on its website.

The Fagersta municipality said in a statement early Friday afternoon that "an assailant armed with a sword has entered Brinellskolan and wounded several people".

Police said they had received reports of the attack just after 2:00 pm (1200 GMT).

Students, just back from their summer holidays, were in lockdown at the school and several other nearby schools for more than three hours before being let out.

Swedish broadcaster SVT reported that the perpetrator had a previous assault conviction and wore a helmet and carried a sword -- reminiscent of an October 2015 school attack in the western town of Trollhattan in which a sword-wielding 21-year-old killed three people in a racially motivated attack.

On that occasion the attacker wore black clothes, a Darth Vader-like mask and a German World War II helmet.

First day of school

Images on public broadcaster SVT on Friday showed multiple ambulances and police cars parked outside the school as well as a police helicopter.

The school has around 450 students, in a town of around 12,000 inhabitants.

Nellie Strandberg, a 16-year-old student at the school, said she was on her way to the school's library when the assailant entered the school.

"We were just going to collect some things and get ready for Monday. Then I see I guy who's bloody all down his back," she told newspaper Dagens Nyheter.

"We asked what happened. My teachers didn't answer, they didn't want to say anything. Then my friend said somebody had a big knife," she added. 

In May, the municipality announced that students at Brinellskolan had been sent home following a threat to the school.

A TikTok account reportedly belonging to the attacker was being investigated by police, according to media. The account has been taken down.

AFP was able to view it before it was taken down and it had several videos referencing school attacks. The last update showed a photo of a sword.

'Serious incident'

Prime Minister Ulf Kristersson told AFP in a written statement that "a serious incident has taken place today at a school in Fagersta, just after the summer holidays."

"We do not yet know what lies behind the attack, but we do know that the police are working extremely intensively," Kristersson said.

Magdalena Andersson, leader of the opposition Social Democrats, lamented the "terrible news" from Fagersta, in a post on X.

"When violence takes place at a school, I know it impacts everyone in our country. All of Sweden stands with Fagersta in this difficult time."

Sweden has suffered several other high-profile attacks at educational institutions.

In February 2025, a 35-year-old man killed 10 people at an adult education centre in Orebro -- Sweden's worst mass shooting.

In March 2022, an 18-year-old student stabbed two teachers to death at a secondary school in the southern city of Malmo.