A teenager who planned to blow up his school will be charged with attempted aggravated murder after six bombs were found in his bedroom.

Grant Acord, 17, planned to attack his school in Oregon in a plot “forged and inspired” by the 1999 mass shooting at a high school in Columbine, Colorado, said Benton County district attorney John Haroldson.

Acord will be charged as an adult and also faces six counts of manufacturing and possessing a destructive device after investigators found the six bombs in a secret compartment in his bedroom, Mr Haroldson said.

Acord was taken to a juvenile jail on Thursday night after police received a tip that the youth was making a bomb to blow up West Albany High School.

Mr Haroldson said Acord had written plans, a checklist and a specific timeline for the attack. Devices found included pipe bombs, Molotov cocktails, a Drano bomb and a napalm bomb, he said.

Police found no bombs during a search of the high school. Mr Haroldson said he was not aware that the youth had any major problems at school.

“In any case that you have a young person that in essence plans to take a video game approach to killing people at school, you have to take a close look at the mental health issues,” he said.

“And the process will certainly provide for that once he’s represented by counsel.”

The district attorney said it did not appear the teenager was targeting a specific person or group of people. He said Acord would probably appear in court tomorrow.

“I can’t say enough about how lucky we are that there was an intervention,” he said.