A rectangular olive-green box with the words "Front Toward Enemy" raised the suspicions of workers at a suburban Denver Goodwill.

Arvada police are investigating a Claymore land mine found in a Goodwill donation box Tuesday that forced the evacuation of a strip mall.

Police say the device didn't go off in the donation box and no one was hurt.

Police Sgt. Jeff Monzingo says it's unclear whether the device was operational or where it came from. No suspects have been identified.

Authorities say a bomb squad disposed of the device, but it wasn't immediately clear if it was detonated or defused.

Claymore mines were widely used during the Vietnam war.