The FBI on Friday warned all banks and financial institutions in the northeastern United States to be on alert for possible suicide attacks from the Al Qaeda terror network.

Officials said they were acting with "an abundance of caution" and they had no information about plots or threats to any specific financial institution.

Banking regulators did not order banks to close. The Treasury Department, which worked with the FBI on the warning, is monitoring the situation closely.

A U.S. official, speaking on condition of anonymity, said the warning is the result of information the intelligence community received from interviews with captured Al Qaeda suspects from Afghanistan. The official said that information led law enforcement agencies to fear a suicide attack.

Fox News has learned that top Al Qaeda leader Abu Zubaydah, who is in American custody and has been undergoing interrogation, was one of several sources who provided information that prompted the FBI warning. Zubaydah didn't offer details of a specific attack, but he acknowledged that "this is one of the things they had in mind," an official said.

Abu Zubaydah was one of Usama bin Laden's top planners of terrorist operations, having knowledge of Al Qaeda plots and operational cells. He was captured by Pakistani and U.S. authorities in Pakistan a few weeks ago and is recovering from gunshot wounds he received in the raid.

The information was given to the FBI which, along with the Homeland Security Office at the White House, decided to remind financial institutions of the need to be vigilant.

The FBI warning went to more than 1,200 banks and savings institutions and to law enforcement in Virginia, Maryland, Delaware, Pennsylvania, New York, New Jersey, Connecticut, Massachusetts, Rhode Island, Maine, Vermont, New Hampshire and the District of Columbia.

In Pittsburgh, Attorney General John Ashcroft noted that no specific institutions were named and there were no specific threats. The information "may or may not be reliable," Ashcroft said.

The attorney general defended issuing the warning even without a specific threat.

"Our policy is to share information with appropriate authorities and the American public when we have threat information that merits their attention," Ashcroft said. "We believe that this information sharing disrupts and prevents terrorist activity."

The FBI warning went to banks and law enforcement agencies in Virginia, Maryland, Delaware, Pennsylvania, New York, New Jersey, Connecticut, Massachusetts, Rhode Island, Maine, Vermont, New Hampshire and Washington, D.C.

The FBI said the decision to issue the warning came after discussions among the Justice Department, Office of Homeland Security and the Treasury Department.

The nation's threat status remained at "yellow," the midrange of the new system of color codes assigned by the Justice Department and Office of Homeland Security. The threat status for the Northeast similarly was unchanged at yellow, the FBI said.

A U.S. official said it was significant that both the region and the banking community itself remain on "yellow alert," meaning the threats did not meet the criteria for a higher alert. To require an orange alert, the threats would have had to include a specific time and date and have been corroborated and credible, the official said.

The FBI announcement came a few hours after the Treasury Department blocked financial assets belonging to a Pakistan-based group and nine people believed to have provided financial support to Usama bin Laden's Al Qaeda terror network.

The alert came as the International Monetary Fund and World Bank convened for their spring meetings in Washington.

A coalition of anti-war, anti-globalization protesters is expected to converge in the nation's capital this weekend to demonstrate against American military and economic policy.

The Federal Deposit Insurance Corp. said there were 613 FDIC-insured savings and loans in the Northeast and 650 FDIC-insured banks. The savings institutions in the region account for roughly one-third, or $433 billion, of the total $1.3 trillion in assets of all FDIC-insured S&Ls. Banks in the region have assets of $2.3 trillion out of $6.6 trillion held by all FDIC commercial banks.

FDIC's definition of the Northeast region includes all the states in the FBI warning except for Virginia. The FDIC region also includes the Virgin Islands and Puerto Rico — which were not part of the FBI warning.

Friday's warning also came on the seventh anniversary of the bombing of the Alfred P. Murrah federal building in Oklahoma City.

Earlier in the week, a bomb threat was received against an unspecified national bank in downtown Washington. Many bank branches shut down but there was no explosion. Police later said the threat was a prank by a 13-year-old Dutch boy.

The Associated Press contributed to this report.