BREMERTON — Police at Naval Base Kitsap are investigating the discovery of razor blades apparently staged as traps aboard vessels at Puget Sound Naval Shipyard.

Seven razor blade “traps” have been found. First, in January 2015, for which evidence was discarded as it was thought to be an isolated incident, and then six in April.

No injuries have been reported at this time.

Examples of the traps include: 4-5 razor blades built into masking material; several razor blades wedged between a black plastic box and keel block pointing straight up; and razor blades wedged between two lockers with their sharp side facing outward.

A safety alert was issued by the shipyard on April 17 following discovery of staged razor blades on April 15

Safety stand-downs and briefings were conducted April 20-21, as were inspections of all ship spaces.

All shipyard personnel have been asked to inform their supervisor if they hear or see anything related to this issue.