Around 10 people were killed Tuesday in a shooting at an education centre in Sweden, including the suspected gunman, police said after the rare gun attack on a campus in the Nordic nation.

Authorities had initially said that several people were wounded in the violence at Campus Risbergska, a secondary school for young adults in the town of Orebro, but had not reported any fatalities.

School attacks are relatively rare in Sweden, but the country has suffered shootings and bombings linked to gang violence that kill dozens of people each year.

"Around 10 people have been killed today," Orebro police chief Roberto Eid Forest told reporters, adding that police could "not be more specific" about the number. "The suspected assailant is not known to police."

He said police were not aware of a motive yet.

Hospital treats wounded

Forest said police received the first reports of a school shooting at 12:33 pm (1133 GMT), but could not specify how it unfolded nor whether it occurred inside or outside the school.

Two Campus Risbergska teachers, Miriam Jarlevall and Patrik Soderman, told newspaper Dagens Nyheter they heard gunfire in a hallway.

"Students came and said someone was shooting. Then we heard more shooting in the hallway. We didn't go out, we hid in our offices," they said.

"There were a lot of gunshots at first and then it was quiet for a half-hour and then it started again. We were lying under our desks, cowering."

Some witnesses told Swedish media they heard what they believed to be automatic gunfire.

Police said they believe the gunman acted alone.

Swedish television channel TV4 meanwhile reported that police had raided the suspect's home in Orebro late on Tuesday afternoon.

It said the suspect was around 35 years old and had a license to carry a weapon and no criminal record, but did not provide any details about his identity.

Police have not confirmed that information.

Police said they were investigating "attempted murder, arson and an aggravated weapons offence".

They urged members of the public to stay away from the area, or keep inside their homes.

Schools in lockdown

Students in several nearby schools as well as the one in question had been locked in for several hours "for safety reasons" before gradually being released, police said.

"It is a very painful day for all of Sweden," Swedish Prime Minister Ulf Kristersson wrote on X.

"My thoughts are also with all those whose normal school day was replaced with horror. Being confined to a classroom fearing for your own life is a nightmare that no one should have to experience."

He said the government was "closely monitoring developments".

A mother whose son was kept indoors at his nearby school for several hours during the police operation told AFP she was "shocked" and "angry".

"My son is at this school behind us, they're locked in too. They have to hide, so I'm waiting for them to evacuate," Cia Sandell, 42, said.

"This is crazy, totally crazy. I'm angry, I'm shocked. This shouldn't happen," she said.

Though such shootings are rare, several other violent incidents have struck Swedish schools in recent years.

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

Two months earlier, a 16-year-old was arrested after wounding another student and a teacher with a knife at a school in the small town of Kristianstad.

In October 2015, three people were killed in a racially-motivated attack at a school in the western town of Trollhattan by a sword-wielding assailant who was later killed by police.