Under a wartime security plan dubbed Operation Atlas, more police officers have been stationed at transportation hubs, including bridges, tunnels, railway stations and major subway stations.

A heightened police presence was also in place in some of the major news organizations in the city.

Most major television stations, newspapers and other news outlets in the city will receive greatly enhanced protection before the United States begins an offensive against Iraq, a police source said.

The move is precautionary rather than a response to any definite terrorist threat, said the source.

The first steps in the NYPD plan to boost security were taken as the rest of the nation followed the city's lead by raising the terrorist threat level from Code Yellow to Code Orange on Monday.

New York City has been at level orange, or "high" risk of attack, since Sept. 11, 2001, but security was still boosted immediately after US President George W. Bush told Saddam Hussein on Monday night to leave Iraq within 48 hours or face war.

In the days ahead, the NYPD expects to implement other aspects of the 5-million-dollar-a-week security package by offering enhanced protection to houses of worship, increasing the police presence outside key financial institutions and beefing up police manpower by requiring some detectives and members of the Organized Crime Control Bureau who normally work in street clothes to report for uniform patrol.

Other security measures include offering greater protection to bridges, tunnels, ferries and the waterfront and evaluating Operation Atlas three days after it begins.

Asked by the federal government to deploy National Guard troops to protect sensitive facilities, New York Governor George Pataki raised the terror alert level to orange in New York state, starting 24-hour operation in the state Emergency Management Office.

Pataki announced on Tuesday a multi-agency security plan called NY Shield. He said he believed no state is better prepared to prevent attacks than the State of New York.

At a press conference on Tuesday afternoon, Mayor Michael Bloomberg, while warning that the city will continue to be at risk for terrorism, urged New Yorkers to go about their lives as normal.

"Although conventional wisdom and simple prudence demand that we take additional precautions at this time, New York will continue to be on the front line against terrorism," Bloomberg said.

"What I'd like to ask of every New Yorker is this: go out and live your lives. If we don't -- if we start to cancel our plans, feel scared instead of feeling alive -- then no attack would be necessary because we will have already lost," he added.

Also on Tuesday, the Federal Aviation Administration (FAA) issued a new set of flight restrictions for the skies over New York.

Under the new rules, a so-called "air defense identification zone" was imposed in 30-nautical mile (55.6 km) rings around the city's three airports of Kennedy, Newark and LaGuardia.

Pilots flying in the zone, which goes up to 18,000 feet (5486 meters), are required to file a flight plan even if they are flying under visual flight rules. All pilots in the zone must also stay in communication with air traffic controllers.

The new rules will give the FAA a better handle on exactly which aircraft are in the area around New York City. The Defense Department is also expected to be patrolling the skies with fighter jets, a common occurrence in the months after Sept. 11, 2001.

(Xinhua News Agency March 19, 2003)