Investigation: U.S. releases suspects' photos

SUMMARY:

Federal investigators released photographs of the 19 men who they believe hijacked the four airplanes involved in the September 11 terrorist attacks on the United States, calling on people who may have had contact with them in the past to pass on their information to the FBI.

Meanwhile, U.S. Treasury Secretary Paul O'Neill said Thursday there has been progress in "finding and freezing" the assets of terrorist suspect Osama bin Laden.

Elsewhere, a document tied to at least two of the suspected hijackers contains reminders and "rules of engagement" for carrying out a strike against the enemy, a law enforcement source said.

And an FBI advisory sent out last week to the American Trucking Association cited unconfirmed threats involving the "use of chemical, biological, and/or radiological/nuclear WMD (weapons of mass destruction)." The advisory called on truckers and workers at hazardous waste facilities to be on the lookout

UPDATE:

FBI Director Robert Mueller said the photographs have been matched to passenger lists for the four hijacked flights, but investigators are checking to see whether the men may have used false identities. Mueller said one or more of the men have ties to al Qaeda, the organization headed by Osama bin Laden. (FBI photos)

•  Summary   •  Update   •  Key questions   •  Who's who   •  Impact

Asked if there had been any progress in finding the assets of bin Laden, O'Neill said, "Yes, both finding and freezing, and not just by the U.S. but by other governments."

O'Neill did not elaborate on what had been found or where, but said "serious money is being blocked now." (Full story)

The "rules of engagement" document was found in a car left behind at the airport in Portland, Maine, where two of the suspected hijackers -- identified by U.S. investigators as Abdul Aziz al-Omari and Mohamed Atta -- boarded a flight to Boston September 11.

The photocopied document was originally handwritten in Arabic, the source said. It includes the instruction "to strike your enemy above his neck" and appears to be a sort of self-reminder to the hijackers. (Full story)

At least 18 people were arrested in several states in connection with alleged efforts to fraudulently obtain commercial trucking licenses allowing the transportation of hazardous materials, authorities said Wednesday night. Citing the potential for other terrorist attacks, the FBI is checking the records of all truck drivers licensed to carry hazardous materials, including explosives and poisons.

KEY QUESTIONS:

How viable are fears about more terrorist attacks? Click here for more.

How will the expansion of law enforcement powers affect Americans' civil liberties? Click here for more.

How are people identified as terrorists communicating with each other? Click here for more.

How are law enforcement authorities using technology such as encryption tools to hunt terrorists? Click here for more.

What groups are U.S. investigators focusing on, and what are their aims? Click here for more.

How would law enforcement authorities go after financial assets of people identified as terrorists? Click here for more.

How did the September 11 attackers evade U.S. intelligence? Click here for more.

WHO'S WHO:

George W. Bush: U.S. president

Colin Powell: U.S. secretary of state Click here for more

Condoleezza Rice: National security adviser Click here for more

John Ashcroft: U.S. attorney general

Robert Mueller: FBI director Click here for more

George Tenet: CIA director. Click here for more

Osama bin Laden: U.S. authorities have named bin Laden, a wealthy Saudi exile living in Afghanistan, as the prime suspect in masterminding the September 11 attacks. Click here for more

IMPACT:

Information gained from the investigation could lead to fundamental changes in U.S. security and intelligence systems, as well as surveillance laws.