The federal government warned Sunday of possible terrorist attacks against "iconic" financial institutions in New York City, Washington and Newark, N.J., saying a confluence of chilling intelligence in recent days pointed to a car or truck bomb.
The government said the new intelligence indicated the meticulous planning of al-Qaida. Homeland Security Secretary Tom Ridge identified explosives as the likely mode of attack, as opposed to a chemical or biological attack or a radiological "dirty" bomb.
Recently obtained information — including photos, drawings and written documents — led the government to take the unprecedented action of naming specific buildings as potential targets:
_The Citigroup Center building and the New York Stock Exchange in New York City.
_The International Monetary Fund and the World Bank buildings in Washington.
_Prudential financial in northern New Jersey.
"The preferred means of attack would be car or truck bombs," Homeland Security Secretary Tom Ridge said in a briefing with journalists. "That would be a primary means of attack," he said.
The government said the new intelligence indicated the meticulous planning of al-Qaida. Ridge identified explosives as the likely mode of attack, as opposed to a chemical or biological attack or a radiological "dirty" bomb.
Ridge said the government's threat level for financial institutions in just these three cities would be raised to orange, or high alert, but would remain at yellow, or elevated, elsewhere.
The Federal Reserve, the most potent symbol of America's financial strength, was not on the list of threatened buildings.
The government provided a wealth of detail that it had obtained in the past 36 hours to 72 hours, but a senior intelligence official described it only on condition of anonymity. The official described "excruciating detail" and meticulous planning "indicative of al-Qaida."
The official said the intelligence gathered from several sources included security in and around these buildings; the flow of pedestrians; the best places for reconnaissance; how to make contact with employees who work in the buildings; the construction of the buildings; traffic patterns; locations of hospitals and police departments; and which days of the week present less security at these buildings.
To illustrate the level of detail included in the intelligence, the official cited these examples: midweek pedestrian traffic of 14 people per minute on each side of the street for a total of 28 people; that some explosives might not be hot enough to melt steel; and that the construction of some buildings might prevent them from falling down.
The official said he had not seen such extraordinary detail in his 24 years in intelligence work.
The warning is based partly on documentary evidence — obtained during successful CIA counterterrorism operation — that provides clear indications that al-Qaida operatives are casing specific buildings in the financial sector, another official said, also speaking only on the condition of anonymity.
The counterterrorism official said the surveillance was going on before and after the 2001 terrorist attacks, but it remains unclear how recently the operatives were conducting the vulnerability assessments.
Sunday's warning was prompted in large part by Pakistan's capture of an al-Qaida operative several weeks ago and documentary evidence that was later uncovered, the official said. That operative's identity has not been disclosed.
Democratic presidential nominee John Kerry was briefed on the threat by federal authorities late Sunday from a secure phone line provided by the Secret Service. He got the briefing from inside his campaign bus, which was parked next to a ball park in Taylor, Mich., where he just played in a softball game with union workers.
Ridge said it would be up to New York City officials to decide whether to move to the highest level, red. The city has remained on orange since the attacks of Sept. 11, 2001.
In Washington, Mayor Anthony Williams put the whole city on a code orange alert level, although the Homeland Security Department has not officially elevated the alert status for the entire city. The department's warning was tailored just to the city's financial sector.
The threat potential remains through the Nov. 2 elections, Ridge said.
The secretary said the government took the unprecedented step of naming particular buildings because of the level of specificity of the intelligence. "This is not the usual chatter. This is multiple sources that involve extraordinary detail," Ridge said. He said the government decided to notify the public because of the specificity of detail it had obtained.
The NYSE and the Washington institutions were to open for business Monday, with employees expected to report to work. Nearly 10,000 employees work at the IMF and World Bank in Washington, where security was being increased.
Officials in the capital said additional security measures were being put in place at the Bureau of Engraving and Printing, where the nation's money is printed, and the Federal Reserve. Those two buildings were not mentioned by Ridge as potential targets. The nation's central bank occupies an imposing building on Constitution Avenue.
An NYSE spokesman declined comment on security, but increased measures since the Sept. 11 attacks have included barricades on all sides and checkpoints to enter the building. A Citigroup spokesman cited a company e-mail to employees that said they should expect to see tighter security at all of its New York buildings. The 59-story Citigroup Center building is among Manhattan's tallest.
A spokesman for Prudential said the company had increased its security before the threat. He declined to offer details, but said employees were expected to report for work Monday.
This was the first time the color-coded warning system had been used in such a narrow, targeted way, Ridge said at a news conference at department headquarters.
Referring to terrorists who are hostile to the United States, Ridge said, "Iconic economic targets are at the heart of their interest." He said workers at the specific buildings mentioned should get guidance from security officers at each site and remain alert as they go to work.
The government's warning came four weeks before the Republican National Convention in New York, which will draw more than 30,000 people, including top government officials and the president.
Ridge sidestepped a question about whether the convention should go ahead — its main item of business is formally nominating Bush. Ridge said only that New York already operates at an extraordinary level of security and the city would draw additional protective measures from the government as a national security event.