Liberty High School being closed Friday due to anonymous threat on social media app

RENTON, Wash. -- Liberty High School classes were being canceled Friday as a precaution because of an anonymous threat to "shoot up" the school that was posted on the After School social media app, authorities said Thursday.

"Someone posted they were going to shoot up Liberty High School's assembly scheduled for tomorrow," a King County Sheriff's Office spokesman said, and the district superintendent decided to cancel school.

The After School app lets people anonymously post messages to their school community.

Detectives are trying to determine if the app has the poster's IP address and if they can get it, the sheriff's spokesman said.

The school district said "we cannot verify whether or not the threat is credible. Therefore, for the safety of students and staff, we have made a decision to close Liberty High School tomorrow, Friday, April 21 ... While the closure of school tomorrow is disruptive, we believe it is in the best interest of student and staff safety and will give law enforcement the opportunity to investigate the situation further."