BEDFORD, Mass. — A report of an active shooter at a Massachusetts Air Force base that prompted a brief lockdown and shelter-in-place order turned out to be a false alarm.

A spokeswoman for Hanscom Air Force Base in Bedford, west of Boston, says the report of a shooter came in to security just after 9 a.m. Thursday.

Security personnel investigated and issued the all-clear 16 minutes later.

Spokeswoman Patty Welsh says the false alarm was caused when someone misidentified a piece of equipment being used for an indoor display.

The base does not have any planes, but acquires and develops weapons systems. It is adjacent to, but not affiliated with Hanscom Field, a civilian airport.