The head of Homeland Security, Tom Ridge, held a press conference in Washington on yesterday to announce that the security level for the financial institutions in those areas has been raised, from "elevated" to "high."
Using the color coding introduced by Ridge's department, the alert level is now at orange. It is the second-highest threat level under red.
Ridge said Homeland Security decided to move to the "high" or "orange" level after receiving very detailed information about an imminent threat: "These intelligence reports have provided a level of detail that is very specific. 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."
He named the institutions under threat as the International Monetary Fund (IMF) and World Bank in Washington, the New York Stock Exchange, and several big banking and insurance groups in New York and New Jersey.
A successful terror strike against the IMF or its sister organization the World Bank, or on the world's biggest stock exchange, would be a major publicity coup for Al-Qaeda.
The intelligence suggested the possibility of car or truck bombings. Authorities on today banned truck traffic through the Holland Tunnel, which connects New York's central Manhattan district with the New Jersey shore, close to several of the financial institutions considered to be under threat.
Ridge's announcement touched off a wide range of other precautions as well.
Municipal authorities in New York and New Jersey have introduced tighter security screening of employees and visitors to buildings in the central city areas. Extra parking restrictions, traffic checks, and extra policing of public and landmark areas have also been added.
The measures are expected to significantly complicate the lives of hundreds of thousands of people working in the area.
Ridge did not say directly where all the intelligence information was coming from. But he gave a hint when he mentioned Pakistan at his press conference: "The reports that have led to this alert are the result of offensive intelligence and military operations overseas, as well as strong partnerships with our allies around the world, such as Pakistan."
According to an article published today in "The Washington Post," the information comes from documents discovered after Pakistani and U.S. forces jointly raided a suspected Al-Qaeda cell in Pakistan last week, arresting several people.
Other media ("The New York Times") quote U.S. officials as saying that information was assessed in conjunction with other intelligence gathered over the past weeks from sources in Afghanistan, Saudi Arabia, and Pakistan.
For instance, extra details came with the arrest earlier in July in Pakistan of a computer engineer who is believed to have managed an Al-Qaeda communications system.
London-based security analyst Sandy Bell, of the Royal United Services Institute, says that the gathering of the latest intelligence information shows the "huge step forward" which the United States and its partners have achieved since the 9/11 attacks of 2001: "Around the world, in a lot of cases, 9/11 was a wake-up call. And we have found out, in the recent reports, that in order to succeed in a war like this, then there must be a coordinated response. And I think the first step we have seen is people starting to cooperate and coordinate with each other, [as well as] various technologies put into place. I think everybody has moved forward on this."
Experts say intelligence-gathering remains complicated by the fact that Al-Qaeda is not a monolithic organization with a centralized structure. Even when intelligence workers succeed in penetrating Al-Qaeda cells, they do not get a complete picture of the overall organization.
Daniel Neep, also of the Royal United Services Institute: "We have to bear in mind the extent to which Al-Qaeda has evolved in the last few years. It is no longer simply the old Al-Qaeda network which had Osama bin Laden as its head. It is a much looser-knit and diverse network. And 'Al-Qaeda' is often used as a sort of brand name, rather than being indicative of a high-level organization. What we think about as Al-Qaeda, with a global reach, is effectively in many cases -- particularly in the Middle East -- local groups."
Ridge said the intelligence in this case has not provided a time frame for a potential attack on the Washington and New York financial institutions. But he said the need for preemptive action is still urgent.