NEW YORK (AP)  -- Police, fire, Coast Guard and Port Authority officials are among those working on a nuclear training exercise in New York Harbor.


Steve Sandberg Reports

New York Police Department Commissioner Ray Kelly says crews will try to detect a nuclear device on a vessel headed into the harbor on Friday. The crews will use equipment received from federal authorities to combat terrorism. The device used Friday will be harmless.

The exercise will last about six hours. More than 100 people will be involved.

The exercise is among the largest collaborations among agencies in the area, including police from Perth Amboy, N.J.

Police Commissioner Raymond Kelly says these types of anti-terrorist exercises are conducted regularly but this one may be the biggest in terms of the number of other agencies that are participating.

Officials say there are seven choke points in the city and three are being tested Friday: the Verrazano Bridge, the Outerbridge Crossing and the George Washington Bridge.