Police say they’ve made “interesting” finds at the home of a masked man who killed a male student and teacher and injured at least two others in a sword attack at a Swedish school.

Police spokesman Thomas Fuxborg said Thursday the 21-year-old unnamed attacker, who carried more than one weapon, including "at least one knife-like object," died after being shot by police following the attack. The spokesman did not elaborate on what "interesting" things were found in the attacker's home.

Law enforcement arrived at the scene to find the teacher already dead and two students, aged 11 and 15, and another male teacher wounded. The second victim was one of those students.

The attack took place at around 10 a.m. at the Kronan school’s café in Trollhattan, north of Goteborg, Sweden's second-largest city.

“People inside locked themselves inside class rooms, in cleaning cabinets,” Fuxborg added.

Laith Alazze, a 14 year-old student at the school, said at first he thought the attacker was part of a Halloween prank.

"One of my friends walked over to him to challenge him, but when we saw he stabbed him [the teacher], we ran away," Alazze told local media.

“We were quite shocked, all of us,” another student added. “We started to cry, we panicked,” she said.

Just hours before the attack, the school had held a meeting to discuss teachers' worries that the school was too open, with a cafe for adults that meant the school could not control who comes in, according to Swedish media.

The Dagens Nyheter newspaper said students must go through the cafe to reach the school's own cafeteria and other parts of the building.

The school has 400 students from preschool to high school. A live feed on the website of the local Goteborg Tidning daily showed people standing outside a red-brick building with police cars and ambulances parked outside.

Swedish Prime Minister Stefan Lofven, who headed to Trollhattan, described Thursday as a "black day."

"My thoughts go out to the victims and their families, the students and staff, and the whole community that has been affected," Lofven told the Associated Press. "No words can describe what they are going through right now."

Sweden's King Carl XVI Gustaf says the Scandinavian country "is in shock,” adding the royal family had received the news "with great dismay and sadness."

The Associated Press contributed to this report.