NEW YORK - (AP) - The federal government has begun rolling out newX-ray machines at New York City airports that will give securityscreeners a peek beneath travelers' clothing.

Some passengers at Kennedy Airport became the first to bescanned Thursday in advance of a more formal rollout Friday.

The device is called a "backscatter" X-ray. It is one of twotypes of whole-body scanners that allow screeners to see if someoneis carrying a weapon - or just a few extra pounds.

The Transportation Security Administration says people whoobject to screeners viewing a computerized representation of theirnaked body will be given a pat-down instead.

The introduction of the machines will be slow, with just ahandful coming to JFK, Newark and LaGuardia airports in the nextfew weeks.

Right now, the TSA has around 300 of the scanners deployed at 61airports.