WASHINGTON, Aug. 1 - The Bush administration on Sunday declared a high risk of terrorist attacks against financial institutions in the New York City and Washington areas after receiving what it described as alarming information that operatives of Al Qaeda had conducted detailed reconnaissance missions at certain sites.
Intelligence information gathered and analyzed since Friday, intelligence officials said, indicates that Al Qaeda has moved ahead with plans to use car bombs or other modes of attack against prominent financial institutions, including the New York Stock Exchange and the Citigroup buildings in Manhattan; Prudential Financial in Newark; and the International Monetary Fund and World Bank in Washington. There was no indication of when an attack might occur, although federal officials said it would probably be in the "near term.''
Intelligence officials said they believed people associated with Al Qaeda had studied these institutions repeatedly both before and since the attacks of Sept. 11, 2001, collecting detailed information on things like building security measures, architecture, pedestrian traffic, access ways and nearby shops that provided cover. Officials involved with the investigation in New Jersey said suspects were found with blueprints of the Prudential site and may have conducted a "test run" for an attack in recent days.
In response, the Department of Homeland Security raised the threat level to code orange, or "high risk," for the financial sector in New York City, northern New Jersey and Washington. It was the first time that the color-coded public threat system, often maligned for being too vague, has targeted a specific sector or region.
While the administration has issued terrorist warnings from time to time, officials said Sunday's announcement was more dire than in the past because the threat information was highly unusual in its specificity and, in the words of one senior intelligence official, "chilling in its scope.''
After past terror warnings, critics have at times accused the Bush administration of exaggerating the threat for political purposes. But on Sunday, few prominent Democrats were making that charge, and many Democrats appeared to take the threat seriously. The code-orange announcement, by Tom Ridge, secretary of the Department of Homeland Security, sent immediate tremors through financial, political and law enforcement worlds, with reverberations from Wall Street to the presidential campaign trail.
In New York and New Jersey, stepped-up security was expected to complicate the start of the workweek on Monday. Tens of thousands of employees, customers and visitors to Wall Street, Midtown Manhattan and downtown Newark were warned to expect tighter personal screening, closer scrutiny of backpacks and packages, more parking and traffic restrictions and other disruptive precautionary measures. [Page A11.]
Mayor Michael R. Bloomberg said teams of officers would be posted at "sensitive and symbolic" sites throughout New York City, including landmarks, major subway stations and train and bus terminals, and on bridge and tunnel approaches, where trucks and other large vehicles are to be halted at random and searched for explosives.
In New Jersey, Gov. James E. McGreevey said the state would immediately deploy antiterrorist officers on highways, commuter trains and ferries and begin intense inspections of trucks within 20 miles of the targeted buildings. A thousand state investigators were assigned to work on the case.
Mr. Ridge said the federal government was working with private financial institutions in New York and Washington and taking steps of its own to intensify security. He also asked for increased public vigilance.
"The quality of this intelligence, based on multiple reporting streams in multiple locations, is rarely seen and it is alarming in both the amount and specificity of the information," Mr. Ridge said.
Unlike last December, when officials raised the threat level to orange because of concerns about international flights over the Christmas and New Year's holidays, intelligence officials said they had no information to conclude an attack was now imminent and no specific indication about when one might be carried out.
The elevation of the threat level for the financial institutions was set off by the recent arrest of a Pakistani computer engineer who may have been involved in Qaeda communication efforts. A senior American intelligence official, while not discussing the source of the information, said analysts were reviewing recently discovered documents that amount to "a potential treasure trove." Officials emphasized that the threat information went beyond intelligence "chatter" picked up from intercepted communications or Internet traffic, which has formed the basis for past warnings.
Several episodes in the United States have recently drawn scrutiny from counterterrorism officials, including the apprehension of a Pakistani woman in Texas with a suspicious passport as well as reports from passengers on a recent flight to Los Angeles about odd activity by a group of Syrian musicians. But officials said that neither of these incidents was a direct factor in the decision to go to Code Orange.
The information uncovered in recent days overlapped with broader concerns that Al Qaeda might plot an attack on or before the Nov. 2 presidential election in an effort to repeat the disruption caused by the Madrid bombings in March. Officials said they believed that senior Qaeda leaders along the Afghan-Pakistani border, including Osama bin Laden, were personally involved in such plots.
Mr. Ridge said he was concerned that Al Qaeda might seek to attack financial institutions in one of three ways: the physical destruction of a building, an outside cyberattack intended to cripple financial markets or an internal attack that would allow someone within an organization to disrupt its operations. From the intelligence gleaned so far, he said, "the preferred method of attack or what's being suggested in the reporting is car and truck bombs - the physical destruction or attempted physical destruction of these facilities."
Like the World Trade Center, financial targets like the New York Stock Exchange and the World Bank are seen as attractive to Al Qaeda largely for symbolic reasons in its effort to wage psychological warfare against the United States, officials said.
"Even the destruction of a single building is not going to undermine the greatest and strongest economy in the world," Mr. Ridge said. "So, to a certain extent, they are almost iconic. They're visible targets perhaps known around the rest of the world."
Officials said they hoped that public scrutiny might help to disrupt a plot, as happened in December 2002, when an alert flight attendant on a trans-Atlantic flight saw Richard Reid trying to light an explosive in his shoe. Or public attention might even prompt terrorist to call off a plot, officials said, as they suspect happened when an Ohio truck driver suspected of surveying the Brooklyn Bridge in 2003 told associates in Pakistan that security was "too hot."
Intelligence officials said they were most concerned about what they described as the fresh evidence that Qaeda associates had conducted reconnaissance missions against important financial targets.
Al Qaeda is long known to have undertaken surveillance of its potential targets. But intelligence officials said they were struck by the detail in recently uncovered evidence, showing Al Qaeda to be focused, patient, disciplined and committed in its desire to attack prominent American targets.
A senior administration official, speaking on condition of anonymity, said there was evidence of reconnaissance missions at all five of the financial institutions cited by the Department of Homeland Security. "This information is about as specific as you can get," the official said.
Intelligence officials listed several dozens pieces of information that they said Qaeda operatives had collected in their reconnaissance missions on security procedures and vulnerabilities at financial institutions. These included the flow of pedestrian traffic, possible escape routes, elevator schedules, neighborhood landmarks, the patterns and number of security personnel, details on surveillance cameras and architectural details that would influence how a building might fare in a bombing, officials said.
"The new information is chilling in its scope, in its detail, in its breadth," said a senior intelligence official, speaking on condition of anonymity. "It also gives one a sense the same feeling one would have if one found out that somebody broke into your house and over the past several months was taking a lot of details about your place of residence and looking for ways to attack you."
Mr. Ridge said he believed toughened federal security measures since the Sept. 11 attacks, including the use of air monitors to detect biological threats, explosive-sniffing dogs, beefed-up undercover and emergency response teams and other measures, have left the country better prepared to defend itself against a possible attack.
"These added security measures mean that from curb to the cockpit, at our ports of entry and borders in between, and our public places in cyberspace, on air and land and sea, we are better protected than we ever have been before," he said.
But the final report of the Sept. 11 commission released last month said wide-scale reforms in intelligence-gathering and domestic protection were needed to predict and prevent another attack, and the White House and Congress are grappling with how that might be best accomplished.
White House officials said Sunday that President Bush was likely to move ahead on Monday with plans to announce an executive order addressing some of the weaknesses in the nation's defenses identified by the commission. The officials declined to be specific about those plans, but they said Mr. Bush would also respond to the commission's call to create the post of national intelligence director and establish a counterterrorism center within the White House to coordinate the response to threats at home and abroad.
David Kocieniewski contributed reporting from New Jersey for this article and Richard W. Stevenson from Washington.