If you see increased police presence near certain bridges throughout the city over the next few days, don't be alarmed.
New York City Police and first responders will be conducting a "dirty bomb'' training exercise.
The 5-day exercise involves hundreds of personnel from 150 law enforcement and other first responder agencies in the tri-state area.
It will be conducted on land, including the rail and highways, and on the waterways.
The effort is designed to test the ability to detect and interdict radiological material that could be used in a terror attack.
The exercise begins Tuesday and runs through Saturday. Expect increased police presence between 11 a.m. and 3 p.m. at the Macombs Dam Bridge, the 138th Street Bridge, the 225th Street Bridge, the 155th Street Bridge and the Third Avenue Bridge.
A similar exercise will be underway in New Jersey during the same time. The New Jersey State Police Office of Emergency Management and its County OEM partners will test first responder deployment and response procedures near road, rail and waterway areas throughout Bergen, Hudson, Essex, Passaic, Morris, Union and Middlesex counties.
Traffic is not expected to be affected by either drill.