Two teenage girls arrested Wednesday are accused of plotting "a mass casualty attack" at Memorial High School in Spring Branch ISD, according to authorities. The Spring Branch ISD police department was initially notified by the FBI of a potentially credible threat against the school on Tuesday and arrested the student involved,

Two high school students in the Houston area are in police custody and accused of plotting a “mass casualty attack” at a Spring Branch ISD campus, according to the FBI’s Houston office.

Evidence suggests their intent was to carry out acts of violence at a school in the Spring Branch Independent School District, law enforcement said.