Live updates: Shooting at Perry High School in Iowa

Police officers located “an improvised explosive device” inside Perry High School in Iowa while undergoing a search of the building following the shooting, according to Assistant Director Mitch Mortvedt of the Division of Criminal Investigation.

Iowa’s state fire marshal and the Bureau of Alcohol, Tobacco and Firearms “rendered the device safe,” he said during a Thursday news conference.

“Numerous officers from multiple agencies were able to secure the school and verify no additional threats,” he said.

Mortvedt called law enforcement’s response to the shooting “swift and immediate,” adding that approximately 150 officers from the local, state and federal level responded within an hour of the incident.

“The investigation into this tragedy is ongoing,” he said.