According to police reports, two teenage girls plotted to place a pipe bomb at Memorial High School, but their plan was foiled when a tip came in to authorities.

Two teenage girls accused of planning a "mass casualty attack" at a Houston-area high school were arrested, authorities said. The girls, 15 and 16, were taken into custody on Tuesday. Their names were not released by authorities because they are minors.

The two girls, ages 15 and 16, planned on placing pipe bombs around the school and using guns to then pick off panicking students and teachers, the Montgomery County Sheriff’s Office alleged.