NEW YORK - (AP) - The nation's largest transit agency has beefedup security as a precaution following the suicide bombing inMoscow's subway system.

A spokesman for New York's Metropolitan TransportationAuthority, Kevin Ortiz, says the agency has a "heightened securitypresence" as a result. He declined further comment.

The agency is in charge of New York City buses and subways, aswell as suburban trains, and bridges and tunnels.

Russian authorities say two female suicide bombers blewthemselves up in Moscow on Monday in a subway jam-packed withrush-hour passengers, killing dozens.