Photo: AP

Last week, the Washington Post reports, the CIA forgot that it had placed “explosive training material” under the hood of a Loudoun County, Virginia, school bus. The bus took students to and from school on Monday and Tuesday this week—the material still hidden in the engine compartment.

Officials said that the material had been used in a training exercise involving explosives-detecting dogs at Briar Woods High School over spring break. In a statement, the CIA said that the material “did not post a danger to passengers on the bus.” A technician found the explosive material during a routine maintenance on Wednesday. From the Post:

Loudoun schools spokesman Wayde Byard said the CIA indicated the nature of the material but asked the school system not to disclose it. Byard described it as a “putty-type” material designed for use on the battlefield and which requires a special detonator; such putty, or plastic, explosives — including the well-known C-4 — are used in demolition and are considered stable.

Byard said law enforcement agencies use school facilities on occasion to conduct realistic training exercises, including active-shooter drills.

As part of last week’s training exercise, CIA trainers placed explosive material into the engine compartment of a school bus on Thursday to test a dog’s ability to sniff it out. They also placed the material in parts of the school. Byard said the dog successfully found the material in the engine compartment, but some of the material fell deeper inside the compartment and became wedged beneath the hoses.

He said school bus drivers check under the hoods of their buses before they take them out on the road, but the package was wedged too far deep inside the engine compartment and was the same color as the hoses, so it could not easily be seen.

Twenty six students attending Rock Ridge High School, Buffalo Trail Elementary School, and Pinebrook Elementary School rode the bus over the course of two days with the material still present.

“We’re all very upset by what happened, but we’re going to review everything that did happen,” Byard, the schools spokesman, said. “Obviously we’re concerned. The CIA really expressed its deep concern and regret today, and it was sincere.”