The FBI arrested two teenage girls plotting a “mass casualty attack” using pipe bombs and guns targeting Memorial High School in Harris County, Texas, police said.

Two teen girls are in custody in Texas for allegedly plotting to commit a “mass casualty attack” at a Houston high school.

Two teenage girls from Texas were arrested on Wednesday for allegedly plotting to shoot up and bomb a Houston high school in a “mass casualty attack,” according to local authorities and the Federal Bureau of Investigation.

Two students are now in custody after authorities identified them as being in the planning stages of a mass casualty attack against Memorial High School.