CBS News Correspondent Jim Stewart reports none of the identified hijackers were Iraqi, but some may have belonged to an Egyptian fundamentalist group tied to the attack on the USS Cole.
Powell, at a news conference Thursday, became the first senior Bush administration official to say for the record what many have been saying privately: that bin Laden is suspected of engineering the attacks.
Asked whether he was referring to bin Laden, the Saudi expatriate who runs a terrorist network from Afghanistan, Powell replied: "Yes."
During the press conference, Powell left little doubt the U.S. is convinced bin Laden was behind these attacks and little doubt about what the U.S. plans to do.
"We will go after that group, that network and those who have harbored, supported and aided that network to rip the network up," he said.
U.S. officials say they are drafting plans to attack not just bin Laden, reports CBS News National Security Correspondent David Martin, but the Taliban rulers of Afghanistan who allow him to operate from their territory either killing bin Laden and destroying his camps or forcing the Taliban to turn him over. And, said Powell, that's not all.
"When we're through with that network, we'll continue with a global assault on terrorism in general."
A senior official named the Iranian backed group Hezbollah, which in 1983 killed more than 200 American Marines in Lebanon, and Hamas, which sends suicide bombers against Israeli civilians, as two of the terrorist groups the U.S. intends to go after.
In what could be the first break in the investigation into the crash of United Airlines Flight 93 in rural Pennsylvania, authorities announced Thursday that they have recovered the flight data recorder from the crash scene. Forty-five people were killed aboard the jetliner.
An FBI agent says the recorder was found in the late afternoon in the eight-foot-deep crater caused by the crash. The "black box" will be analyzed by the National Transportation Safety Board.
At the Pentagon, searchers received a signal from the black box of the airliner that crashed there.
But search crews will not be able to retrieve the black box, which could contain information about the last minutes of the hijacked commercial jetliner, until they are able to enter the collapsed area of the Pentagon, where the plane's fuselage rests.
They were to begin moving into the collapsed area sometime Thursday night, said Arlington County Fire Capt. Scott McKay.
Investigators are also looking into the possibility and it's only a possibility that other hijackings may have been aborted. The planes may have been diverted at the last minute after the other hijackings, or the terrorists may have gotten cold feet. There's no direct proof of either scenario yet, but sorting through anecdotal material yields suggestions to that effect.
Names of suspected terrorists with possible ties to bin Laden's organization were found on the passenger rosters of the hijacked planes and intelligence intercepts showed affiliates of bin Laden saying they had hit two targets, sources said.
There appears to have been very little effort if any to hide their identities. At least seven of them, for example, purchased their tickets out of Boston with the same credit card.
Those credit cards and the flight manifests have provided the most significant evidence so far, and have led to what is said by high level federal law enforcement official to be "an ocean of names."
Authorities say they have every reason to believe the hijackers were assisted and sheltered by associates in the United States, but it's not known if those associates still in the U.S. Some of the hijackers were in this country "for more than one year."
While there have been no arrests, Ashcroft said, authorities have interviewed many people in connection with the hijacking of four airliners and the attacks on the World Trade Center in New York and the Pentagon.
A total of 18 hijackers were on the planes, Ashcroft said. There were five on each of two planes and four each on the other two. All have been identified.
The FBI has announced that they will release photographs and names of all 18 hijackers.
He said he was heartened by the public's intrest in tracking down those responsible.
"The FBI is working thousands and thousands of leads," he said.
Ashcroft said the FBI's 800-number hot line had received 2,055 calls. In addition, its Web site (www.ifccfbi.gov) had received more than 22,700 tips, he said.
Ashcroft said authorities believe the hijackers were trained pilots.
A Venice, Fla., man said FBI agents told him that two men who stayed in his home while training at a local flight school were the hijackers. Charlie Voss said the agents identified the men as Mohamed Ata and one known as Marwan.
The FBI interviewed Voss about two men who stayed with him and his wife for a week in July 2000 while taking small-plane flight training at the municipal airport.
FBI agents "informed me that there were two individuals that were students at Huffman Aviation, my employer, and FBI told me they were involved in yesterday's tragedy," Voss said.
The couple accepted the two men as house guests as a favor to the company, Voss said. The men, who stayed just a few days, trained at the airport and came to the house to sleep, he said.
FBI agents obtained information from Internet providers, conducted searches, and questioned people in Florida and Massachusetts. Early evidence, including communications among Osama bin Laden supporters, indicated the attacks were tied to the wealthy Arab and accused terrorist.
Acting on a tip from the FBI, police in Hamburg searched an apartment Wednesday where two men believed to be linked to the terror attacks in the United States once lived, police said in a statement.
Police said the apartment had been uninhabited since February 2001, and that the two men were believed to have lived in Florida from July 2000 to January 2001.
In Boston, law enforcement officials said a hotel room in the Boston area believed to have been used by one of the hijackers was searched by the FBI Wednesday afternoon. The room was vacant but included information linking it to a name on the manifest of one of the hijacked flights.
Law enforcement officials, who spoke on condition of anonymity, said they were investigating whether one group of hijackers crossed the Canadian border at a checkpoint and made their way to Boston, where an American Airlines flight was hijacked and flown into the World Trade Center in New York.
The officials confirmed a car believed to belong to the hijackers was confiscated in Boston and contained an Arabic language flight manual.
Abu Dhabi Television in the United Arab Emirates reported that two men with Saudi Arabian passports and international drivers licenses issued in the UAE were linked to the Mitsubishi sedan found at the Boston airport.
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