Man linked to bin Laden associate arrested in Chicago

CHICAGO, Illinois (CNN) -- A man said to be linked to an associate of Osama bin Laden and wanted in connection with the investigation into last week's terrorist attacks was arrested by federal agents, the FBI confirmed Thursday.

The FBI said a man they identified as Nabil Al-Marabh, 34, who is on the list of people wanted for questioning, was taken into custody Wednesday night outside Chicago. The FBI also was enlisting the aid of banks to follow the money trail in the terrorist attacks while trying to resolve whether the hijackers used aliases of people who still may be alive.

Meanwhile, vowing to "disrupt, interrupt, stop, thwart, curtail" terrorist attacks, U.S. officials overseeing the investigation into the attacks spoke Thursday afternoon at the southwestern Pennsylvania crash site of United Flight 93.

The United jetliner was one of four hijacked planes September 11, along with the two that slammed into the World Trade Center and the one that crashed into the Pentagon.

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

"We believe those passengers on this jet were absolute heroes," FBI Director Robert Mueller told reporters in Shanksville, Pennsylvania, after touring the crash site with U.S. Attorney General John Ashcroft. His comments were the most specific to date in support of the theory that the passengers and crew may have struggled with the hijackers and attempted to seize control of the plane. Authorities believe the jet may have been headed for the White House or the Capitol.

In other developments in the investigation:

-- The number of people being detained on immigration charges for questioning in the probe rose to 115.

-- FBI Director Mueller acknowledged that the perpetrators of the September 11 hijackings and terrorist attacks may have stolen identification of other people.

-- The Los Angeles Times reported an unnamed source as saying FBI and CIA officials were advised in August that as many as 200 Islamists with terrorist leanings were entering the United States and planning "a major assault on the United States."

-- Ashcroft announced that aliens in the custody of the U.S. Immigration and Naturalization Service may now be held for long periods of time before charges are brought, to give investigators more time to question them.

Man obtained license to drive large trucks

Al-Marabh was being held on an INS request and a warrant issued in Boston for assault with a knife. Federal agents had been looking for Al-Marabh since at least Monday, when they raided a Detroit house with his name on the mailbox and arrested three men after discovering false visas, passports and other ID, as well as what appeared to be a diagram of an airport flight line.

VIDEO U.S. investigators are finding that suspected hijackers led 'normal lives' while living in the United States. CNN's Eileen O'Connor reports (September 20) Play video (QuickTime, Real or Windows Media) CNN's Kelli Arena looks at how suspected terrorists gained entry into the U.S. (September 20) Play video (QuickTime, Real or Windows Media)

Al-Marabh had a commercial driver's license issued by the state of Michigan, according to the Michigan Secretary of State's office. That license, issued September 11, 2000, allowed Al-Marabh to operate vehicles weighing 10,000 pounds or more. "He can drive a big truck," said the official.

Additionally, Al-Marabh obtained what is called an "endorsement" the same day that allowed him to transport hazardous materials. The official said he took a test and paid a fee to obtain that endorsement.

The official said the Michigan Secretary of State's office had no records on what kind of work Al-Marabh may have done.

The arrest of Al-Marabh came as the FBI began enlisting the aid of banks to follow the money trail in last week's terrorist attacks. In doing so, investigators are trying to determine if the hijackers used aliases of people who still may be alive.

The FBI sent a list of the alleged hijackers to banks Wednesday asking bank officials to search for any financial transactions involving 21 people wanted in connection with the terrorist attacks.

"The FBI is requesting that all financial institutions check their records for any relationships or transactions with the named suspects," said a "Special Alert" dated September 19 from the Federal Deposit Insurance Corp.

"Any financial institution that identifies such a relationship, such as a bank account, or a transaction, such as a wire transfer, with any of the named suspects should complete and file a suspicious Activity Report ... and immediately contact" the FBI, the alert added.

The list mostly included the names of 19 Middle Eastern men previously identified by the FBI as the suspected hijackers. But the list identified one of those, Khalid al-Midhar, as possibly alive, The Associated Press reported.

Saudi officials have told U.S. officials that as many as four people in their country with similar names or identical names to the hijackers are alive and that some fear their identities may have been stolen. The FBI is investigating, but hasn't reached any conclusions.

In August, al-Midhar was placed on a watch list after U.S. intelligence received information that a man with that name had been seen meeting with associates of accused terrorist Osama bin Laden in Malaysia, officials have said.

Report: U.S. advised of 'major assault'

In another development, The Los Angeles Times quoted an unnamed law enforcement official in Thursday's editions as saying FBI and CIA officials were advised in August that as many as 200 Islamists with terrorist leanings were slipping into this country and planning "a major assault on the United States."

The advisory, passed on by the Mossad, Israel's intelligence agency, cautioned that it had picked up indications of a "large-scale target" in the United States and that Americans would be "very vulnerable," the official said. The paper said it is not known how U.S. authorities reacted to the warning.

The CIA denied that Thursday. "That is utter nonsense," said spokesman Bill Harlow.

On Wednesday, Ashcroft left open the possibility that countries could have supported the terrorists.

During a visit to the Pentagon, Ashcroft sidestepped answering whether investigators had determined a foreign state was involved by saying such terrorist networks in general get backing from governments.

"It is pretty clear that the networks that conduct these kind of events are harbored, supported, sustained and protected by a variety of foreign governments," he said. "It is time for those governments to understand with crystal clarity that the United States of America will not tolerate that kind of support."

Law enforcement officials said the investigation had not made a direct link between last week's attacks and a foreign state, although there was uncorroborated evidence that one of the suspected hijackers met with an Iraqi intelligence officer earlier this year in Europe.

Iraq has denied involvement.