Officers practice security training in Montgomery Co.

SILVER SPRING, Md. -- Commuters are seeing lots of police across Montgomery County Tuesday morning, but not because a crime has been committed. A security training exercise is underway.

The training exercise is not connected to any specific threats. It's one in a series of planned exercises.

More than 180 officers are participating until 7 p.m.

Agencies involved include the following: Montgomery County Police; Montgomery County Sheriff's Office; Montgomery County Fire Marshal's Office; Rockville City Police; Gaithersburg Police; Takoma Park Police; Maryland state Police; Maryland National Capital Park Police; Washington Metropolitan Area Transit Authority Police; Maryland Transit Administration Police; Maryland Transportation Authority; and Federal Air Marshals & Behavior Detection Officers.

K9 teams and SWAT officers also are part of the exercise.

As part of the exercise, some trucks are being inspected on unspecified roadways.

A separate training exercise is being done in Virginia on Virginia Railway Express.

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