Investigation: Arrests made in U.S., Europe

SUMMARY:

Three men and one woman were arrested Friday by anti-terrorist branch officers in connection with last week's attacks on the World Trade Center, the Scotland Yard said.

Meanwhile, a federal judge denied bond Friday for three men arrested this week in connection with the investigation into the September 11 terrorist attacks.

Also, French counter-intelligence officers arrested eight people suspected of belonging to extremist Islamic groups thought to be planning attacks on U.S. interests, the French Ministry said.

And the FBI is enlisting the aid of banks to follow the money trail in the September 11 attacks.

UPDATE:

The men denied bond Friday were arrested on Monday in Detroit and identified in court documents as Karim Koubriti, 23; Ahmed Hannan, 33; and Farouk Ali-Haimoud, 21. All were described as resident aliens and Arabs.

They were arrested after FBI agents went to a Detroit apartment Monday in search of another man, Nabil Al-Marabh, identified as a potential suspect or associate of the 19 hijackers from last week's attacks. Al-Marabh was later arrested outside Chicago, FBI officials said Thursday. Authorities had discovered false visas, passports and other ID, as well as what appeared to be a diagram of an airport flight line.

In England, police also apprehended two men and a woman in west London during a 3 a.m. raid, and then arrested a fourth man in the West Midlands around 7 p.m., the Scotland Yard said.

All four are now being questioned in a central London police station, police said. No nationalities were given of those arrested. (Full story)

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

Meanwhile, U.S. Treasury Secretary Paul O'Neill said a massive effort is under way in cooperation with governments and law enforcement authorities around the world to "begin a closing down of bank accounts" of individuals and groups tied to what he called "terrorist" activities.

Four people have been arrested as material witnesses. About 115 other people are in government custody, being questioned and in some cases investigated for possible immigration violations.

KEY QUESTIONS:

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?

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?

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.