Stockholm, SwedenReuters —

An 18-year-old man armed with a sword attacked students at a Swedish high school on Friday, killing one person and injuring three, and police shot and detained him as media reported the attacker was a former student at the school.

The incident occurred on Friday afternoon at the Brinell high school in the central Swedish town of Fagersta, which has about 13,000 residents. The school had just reopened after summer recess, and for some students, it was their first day.

Police told a press conference that the suspect was an 18-year-old man whom they shot and took into custody on suspicion of murder.

Local police chief Tommy Alriksson said officers responded quickly to the school, which has 450 students ages 16 to 20.