TRINIDAD, Colo. (AP) — Police say they thwarted a plan by two teenagers who wanted to shoot students and teachers at a southern Colorado high school.

Police Chief Charles Glorioso says the department’s school resource officer got a tip Thursday that two boys, ages 15 and 16, planned to carry out the attack at Trinidad High School after winter break. Because of the warning, extra security was in place at three Trinidad schools Thursday.

Glorioso says investigators learned the 15-year-old had been bullied and had said he idolized the Columbine High School and Colorado theater shooters.

The teens were arrested Friday. Glorioso says they planned the attack for a month and a-half, but he wouldn’t release the details of their plot or how they would carry it out.