A student shot six people and one of them succumbed to the wound at Perry High School in the US state of Iowa. Then the accused also took his life, on the first day to the school after the holiday break.
Police said that a "pretty rudimentary" improvised explosive device was found by investigators on the spot and rendered it safe.
Of the six shot by the student, five were students and one a school administrator.
The student who was shot fatally was studying Grade Six in school, which means he was 11 or 12 years old.
On information, police reached the school within minutes of the incident.
Speaking to reporters after the shooting, Iowa police said that on arriving at the spot, they found the suspect with a self-inflicted gunshot wound. He was identified as Dylan Butler, 17, who was armed with a pump-action shotgun and a small calibre-handgun.
Police said that the suspect had "made a number of social media posts in and around the time of the shooting."
Of the injured, one was in a critical condition and four were stable, the police said.
