28, 2001 2:30pm EDT
FBI agents learned the suspects names from the airline passenger logs and found photos from driver licenses, passports, and other identification documents.
While authorities admit they have not completely verified the actual names or citizenship, investigators believe that at least eight were Saudi nationals because of their surnames.
FBI Director Robert S. Mueller III confirmed that at least one of the 19 suspected hijackers was involved in the al Qaeda terrorist network, though he would not give further details.
In a joint press conference, Attorney General John Ashcroft appealed for a "national neighborhood watch" to provide authorities with more clues and information about the 19 suspects.
British Foreign Minister Jack Straw declared a heightened state of alert in England, warning of possible future attacks in London.
"We have to work on the basis that this organization is still there around the world.. and that there continues to be a risk of them making further attacks," Straw explained to the BBC.
Straw and other officials from the Blair administration support the Bush administration's efforts to launch an international investigation into the elusive al Qaeda network.
British investigators currently hold an Algerian national, 27-year-old Lotfi Raissi, who is suspected of training the four hijackers who crashed into the Pentagon. Raissi attended the same flight school as the four hijackers and qualified as a pilot in 1997. He was arrested on September 21 on a U.S. warrant for falsifying information in his application for a pilot's license.
British courts have not confirmed that Raissi is connected to the al Qaeda network. Raissi's lawyers insist that he had no connection to the four hijackers.
Spanish authorities announced that the six Algerians arrested earlier this week were a "dormant cell" of al Qaeda and the dissident Algerian Armed Islamic Group. Police searched their apartments and discovered videos of bin Laden's training camps in Afghanistan, equipment for creating false documents, and diary sketches of plans for a suicide plan.
In the wake of the September 11 attacks, U.S. officials have detained and questioned over 350 people, mostly Arab immigrants, visitors, or Arab-Americans based on a "watch list" of people suspected to have known the 19 hijackers. About 100 detainees are being held on immigration or fraud charges, but reportedly no one has been linked to Osama bin Laden, the prime suspect in the September 11 attacks, or his al Qaeda network.
The FBI said that the 18 Middle Eastern men arrested yesterday for illegally obtaining hazardous material permits were not involved in the terrorist attacks and were released. Based on fears of a chemical or biological attack, investigators will be sent to over 80,000 truck companies that carry hazardous materials.
FBI Director Robert S. Mueller III said that when individuals are released, "they come off the watch list [and] we apologize for taking their time."
Many Congress members and civil rights advocates have criticized law enforcement's tactics and worry that the anti-terrorist investigations may violate constitutional rights.