Investigation: FAA orders background checks

The Federal Aviation Administration has ordered that all airport employees with badge access to restricted areas have their employment histories scrutinized, and the agency may call for criminal background checks on them.

The order requires airlines to check employee records for names that might be on the FBI's watch list of possible terrorist suspects, according to a senior government source. (Full Story)

The FBI has limited the use of crop dusters amid concerns that suspected terrorists might have been plotting to use the seemingly innocuous aircraft for another attack, possibly chemical or biological, according to law enforcement sources.

SUMMARY:

The U.S. State Department will offer up to $25 million in reward money for information leading to the capture of terrorists involved in the deadly September 11 terror attacks.

The reward money is part of a $5.1 billion spending package to deal with the aftermath of the attacks, the first installment of a $40 billion emergency recovery package approved by Congress and President Bush.

The FBI said Saturday it was pursuing 149,900 tips and potential leads in its criminal investigation into the coordinated strikes that destroyed the World Trade Center and severely damaged the Pentagon, killing thousands of people.

The FBI now believes suspected hijacker Abdul Aziz Alomari -- one of the men officials believe was aboard American Airlines Flight 11, which slammed into the north tower of the World Trade Center -- played a "key leadership role" in the September 11 terror attacks, law enforcement sources tell CNN. (Full story)

U.S. law enforcement authorities are also working to extradite a Yemeni man being held in Toronto, who U.S. officials said was carrying three false Yemeni passports aboard a Germany to Chicago flight that was diverted to Canada on the day of the suicide hijackings. The man has been detained in Canada. (Full story)

UPDATE:

Officials familiar with the cockpit voice recorder on United Airlines Flight 93 -- the hijacked jet that crashed September 11 in western Pennsylvania -- say there was a "definite struggle" described as desperate and wild between hijackers and some of the passengers. (Full story)

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

In England, two men and one woman were still detained Saturday by anti-terrorist branch officers in connection with last week's attacks on the World Trade Center, Scotland Yard said.

Police 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.

However, the 29-year-old man arrested in west London was released Saturday, Scotland Yard said.

Authorities declined to explain how the suspects may have been linked to the September 11 hijackings of the two jetliners that were crashed into the twin towers of the World Trade Center 18 minutes apart.

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

Also in Europe, French police on Friday detained eight people suspected of belonging to extremist Islamic groups thought to be planning attacks on U.S. interests in France, that nation's Interior Ministry 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. 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. (Full story)

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? 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.