A teenager suspected of threating against a Norwegian school on the Internet was interrogated and released Monday.
The video posted to YouTube threatened a secondary school in Askoey, near the western coastal city of Bergen, and referred to a gunman who killed eight people and himself in Finland earlier this month, police said.
All of the school's roughly 280 students were searched by police before classes started Monday as a precaution, but nothing dangerous, such as weapons, was found, school officials said.
Askoey Sheriff Odd Dale said the suspect was questioned during the day and released, although they remain under suspicion.
"We haven't gotten to the bottom of this yet," he said. Dale refused to release the suspect's name, age or gender, or whether they had any connection with the school.
Dale said a woman in Britain spotted the YouTube video "with pictures of the school together with a threat. Today's date was also mentioned."
Authorities were alerted to the threat Saturday, police said in a statement.
The posting also included links to school shootings, and a recording of the song "Working Class Hero" by the late John Lennon which has such lyrics as "They hurt you at home and they hit you at school." It did not show who made the video, police said.
Dale said the posting came from one of the up to 3,000 computers owned by the Township of Askoey, and it was not clear whether it was done at a school, library or public office.
On Nov. 7, Pekka-Eric Auvinen, 18, shot dead eight people at the Jokela school in Finland after posting an Internet threat on YouTube. Auvinen died of a self-inflicted gunshot wound.
On Sunday, German police said they had averted a plot by two teens to attack a school in Cologne.
Classmates alerted school authorities to that threat after spotting one of them studying an Internet page with pictures of the 1999 Columbine High School massacre in the U.S., police said. Eric Harris and Dylan Klebold killed 12 students and a teacher, and wounded 23 others, in the Columbine shootings.