A teacher and a young student were killed Thursday morning when a masked man with a sword attacked a school in the Swedish town of Trollhattan.

Police shot the suspect, who is reportedly in his 20s, shortly after the attack started—around 10 a.m. local time. He’s now in a hospital in serious condition. Two wounded male students, ages 11 and 15, were also taken to the hospital and reportedly in serious condition. The BBC reported one of the boys later died.

According to Sweden’s The Local, another teacher and a third student are also being treated at the hospital, and an ambulance crashed into a school wall as it arrived on scene.

Students who saw the masked man initially thought he was joking, according to Swedish TV reports cited by the BBC.

“He had a mask and black clothes and a long sword,” one said.

Another thought the man had been wearing a Star Wars mask.

The Local also ran one teenage student’s harrowing accounts of being chased by the man:

“I was in a classroom with my class when one of my classmates’ sisters called her to warn her that there was a murderer at the school. So we locked the door to the classroom, but our teacher was still outside in the corridor.”

“We wanted to warn him, so a few of us went outside and then I saw the murderer, he was wearing a mask and had a sword. Our teacher got stabbed.”

“The murderer started chasing me, I ran into another classroom. If I had not run, I would have been murdered. I’m feeling really scared. Everyone’s scared here.”

“This is a dark day for Sweden,” Prime Minister Stephen Löfven said in a statement.

[Photo: AP Images]