NEW YORK, Dec. 23 (UPI) -- In the third day of heightened security Tuesday, the United States said it could deploy surface to air missiles around Washington and New York, CNN reported.
Among the measures implemented since Sunday's declaration of a "level orange" security alert, troopers from several states around New York were authorized to ride and patrol commuter trains into New York City, and anti-aircraft missile batteries may be deployed around Washington and New York. A senior Pentagon official said "irregular air patrols" had also been ordered.
Sunday, the Department of Homeland Security raised the level from elevated, or yellow, to high, or orange, the second-highest level on the department's five-color warning system of green, blue, yellow, orange, red.
"There is a continuous stream of reporting, literally from the last two years, that indicates (terrorists') preference or desire to use aircraft as a means of attack," Ridge told CNN.
Some homeland security officials predicted the increased security could last into February, at a cost of about $1 billion per week, much of it in increased overtime costs for law enforcement personnel.