BERKELEY, Calif. (KRON) — A teen boy was arrested on Monday after officers received a tip he was recruiting other high school students to participate in mass shooting and/or bombing, the Berkeley Police Department announced in a Nixle alert. Police received a tip on May 21 that a 16-year-old boy tried to organize a shooting at Berkeley High School.

The boy turned himself in to Berkeley police Monday afternoon. Police said he was arrested on suspicion of “possessing destructive device materials” and “threatening to commit a crime which will result in death or great bodily injury.”

After receiving the initial tip on May 21, officers obtained a search warrant to search the subject’s residence. At the teen’s residence, police found assault rifles, several knives, parts to explosives, and electronic items that could be used to create weapons.

The Berkeley Unified School District issued a statement Wednesday afternoon, stating the boy “did not pose an immediate threat to the Berkeley High School community.” The BUSD said they will conduct their own separate investigation independent of BPD.

Berkeley Mayor Jesse Arreguin also released a statement, calling the threat “disturbing.”

“As the country continues to reel from a horrific school shooting, it was disturbing to hear a similar plot was being planned at Berkeley High School, which was ultimately foiled,” he said. “I am thankful for the Berkeley Police Department for their thorough investigation and the students who spoke out to raise the alarm.”

Police did not release any other information about the subject nor did they say how many students the subject tried to recruit.

The incident remains under investigation.  If you have any information about this incident, please contact the Department’s Youth Services Unit at (510) 981-5715.