N.Y. boosts security after terror warning

Kelly: "We are taking all necessary precautions."

NEW YORK (CNN) -- City officials were taking "all necessary precautions" Tuesday after the FBI informed them of "general threats" against the city, Police Commissioner Raymond Kelly said.

Police and FBI sources said landmarks, including the Statue of Liberty and the Brooklyn Bridge, had been identified as possible targets, although the information did not contain such specifics as when an attack might occur.

New York Gov. George Pataki said that while officials were taking the threats "seriously," people should "go on and go about their ordinary lives" and not give into fear.

"September 11 wasn't just aimed at destroying the two towers and killing thousands of people. It was aimed at dividing us and frightening us and taking away our freedom and taking away our confidence," Pataki said.

"We have to continue to show that courage and show that confidence so we can show the world."

Pataki continued, "We are confident that everything that can be done between the city, the state [and] the federal authorities is being done."

In a statement Tuesday, Kelly would not provide details of the threats.

CNN.COM SPECIAL REPORT  CNN NewsPass Video  Agencies reportedly got hijack tips in 1998  MORE STORIES Intelligence intercept led to Buffalo suspects Report cites warnings before 9/11  EXTRA INFORMATION Timeline: Who Knew What and When? Interactive: Terror Investigation Terror Warnings System Most wanted terrorists What looks suspicious? In-Depth: America Remembers In-Depth: Terror on Tape In-Depth: How prepared is your city?  RESOURCES On the Scene: Barbara Starr: Al Qaeda hunt expands? On the Scene: Peter Bergen: Getting al Qaeda to talk

"It is our policy not to comment on any details relating to threats or our response, as it could undermine our counterterrorism and intelligence operations," he said.

"We are taking all necessary precautions and are communicating with the appropriate law enforcement agencies on both the state and federal levels."

New York has been on a heightened state of alert since September 11. City officials have not said whether they have pushed that alert up another notch.

An FBI spokeswoman said the bureau gave the "uncorroborated" information to the Joint Terrorism Task Force, which is composed of local, state and federal law enforcement agencies in the New York area, during its daily briefing.

The FBI has not issued an alert, she said.

Tuesday morning traffic on the Brooklyn Bridge was carefully scrutinized. Security was stepped up at other bridges as well. Tunnels to Manhattan have been a focus of the heightened state of alert since September 11.

A National Park Service source said security measures on Liberty Island have been increased. The grounds of the Statute of Liberty remain open, but the monument itself has been closed since the September 11 terrorist attacks.

It remains unclear where the detainees who provided the information are being held. Previous terrorism warnings have been based on information obtained from detainees held at the U.S. naval base at Guantanamo Bay, Cuba, and in Afghanistan.

The Statue of Liberty was one of the landmarks named.

The FBI spokeswoman likened Tuesday's threats to similar information that terrorists may be targeting apartment buildings, which led the bureau to advise apartment managers to maintain vigilance.

The warning came a day before 6,000 military personnel and 15 ships were scheduled to arrive in New York for Fleet Week, an annual display of ships and planes that will include the aircraft carrier USS John F. Kennedy.

Ships from Britain, Mexico and the Dominican Republic also were to participate, according to the U.S. Navy's Web site.

The first ship was scheduled to clear the Verrazano Narrows Bridge shortly after 8 a.m. ET Wednesday. The event runs through May 30.

-- CNN correspondents Kelli Arena and Deborah Feyerick contributed to this report.