Attorney General John Ashcroft released on Thursday photographs of the 19 suspected Sept. 11 hijackers, saying that it is part of "a national neighborhood watch" in which they hoped Americans might recognize some of the individuals.

Click to view the suspected hijackers

"It is our hope" that the photos "will prompt others" who see the hijackers or have "been in contact with them to contact the FBI," Ashcroft said.

Investigators have received more than 100,000 tips, Ashcroft said. FBI Director Robert Mueller said the bureau has "over 200,000 leads we are investigating."

Video: FBI Releases Photos of Suspected Hijackers

"We call upon any citizen who has information that may be helpful to contact" the FBI, said Mueller.

Some of the names have slightly different spellings and others have additional names added, compared to the list released by the FBI on Sept. 14.

Mueller said that the FBI is confident that the names and photos were the identities the hijackers had before entering the United States. The FBI director said there was evidence that one or more of the hijackers had had contacts with Al Qaeda, the network associated with accused terrorist Usama bin Laden.

Mueller also said Thursday that preliminary investigation has shown no link between the Sept. 11 attacks and the 20 suspects feds have in custody for allegedly fraudulently obtaining licenses to transport hazardous materials.

The concern about licenses to carry chemicals first surfaced last week when the FBI arrested Nabil Al-Marabh, 34, a former Boston cab driver. Al-Marabh holds a commercial driver's license and is certified to transport hazardous materials.

The FBI appeared to be zeroing in on people who — wittingly or unwittingly — helped the 19 men authorities say hijacked four airliners and crashed them in New York, Washington and Pennsylvania. Nearly 7,000 people are dead or missing as a result.

The Associated Press contributed to this report.