Oops

For at least two days a school bus in northern Virginia has been carrying students with explosive material hidden in its engine compartment. The explosives fell out of a container, which was used by the CIA for training last week.

“During the exercise, explosive training material was inadvertently left by the CIA K-9 unit in one of the buses used in the exercise,” the CIA said in a statement. The agency attested that the explosives were "incredibly stable" and “benign” and didn’t put anyone in danger.

[...]

Loudoun schools spokesman Wayde Byard described the explosive as a “putty-type” material designed for use on the battlefield and which requires a special detonator.

  RT

I guess no one at the CIA took inventory of their explosives and noticed some missing.

...but hey, do what you want...you will anyway.