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.

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

Two teenage girls in the US state of Texas have been arrested for plotting a "mass casualty attack" with pipe bombs and guns, police say. The girls, ages 15 and 16, were planning an attack at Memorial High School in a suburb of Houston, police told KHOU, an affiliate of the BBC's US partner CBS News.