A device "unexpectedly detonated" Thursday during the FBI Philadelphia field office's explosives training, leaving five law enforcement officers injured from multiple agencies, officials said.
FBI Philadelphia was holding the training at the State Correctional Institution–Phoenix in Collegeville, it said in a statement on its Twitter page.
Three bomb technicians with the Montgomery County Sheriff's Office, a bomb technician with the Pennsylvania State Police and a bomb technician with the FBI Philadelphia were wounded, a spokesperson with the FBI Philadelphia field office said Thursday afternoon.
The bomb technicians were taken to area hospitals for treatment, officials said. Their conditions were not clear Thursday afternoon.
Montgomery County said in a statement that its injured personnel included a 14-year veteran with the sheriff's office who was airlifted to Penn Presbyterian Medical Center. Also injured were a 13-year veteran and a 12-year veteran with the sheriff's office. They were treated at Paoli Hospital, county officials said.
NBC Philadelphia reported that two officers were flown to hospitals and that others were taken by ambulance.
The station's helicopter showed a white sedan that appeared badly burned on a grassy field.
The FBI and Pennsylvania State Police are investigating.