ASHINGTON, Sept. 27 ・Law enforcement authorities said tonight that they had found an Arabic language document belonging to the hijackers that appears to be a spiritual and practical guide to preparing for their attacks.

The Washington Post reported on its Web site tonight that the five- page, handwritten document was found in the luggage of Mohamed Atta, who was believed to be a leader of the hijackers, and the authorities said another copy was found in the wreckage of United Airlines Flight 93 in Pennsylvania.

The Arabic translation of the document obtained by the Post showed a chilling message to the hijackers to stick together and overcome their fears in carrying out the terrorist assaults. The document tells the hijackers that "infinite paradise" awaits them. But it also advises them to be careful in carrying out their assignments.

"Check all your items ・your bag, your clothes, knives, your will, your ID's, your passport, all your papers. Check your safety before you leave. Make sure that nobody is following you. Make sure that you are clean, your clothes are clean, including your shoes."

The letter promises: "You will be entering paradise. You will be entering the happiest life, everlasting life. Keep in your mind that if you are plagued with a problem and how to get out of it. A believer is always plagued with problems. . . . You will not enter paradise if you have not had a major problem. But only those who stood fast through it are the ones who will overcome it."

The author of the letter also seemed to be preparing the hijackers for the potential of conflict among them. "Obey God, his messenger, and don't fight among yourself where you become weak, and stand fast. God will stand with those who stood fast."

The excerpts published by the Post also try to try and ease fears of death. "Everybody hates death, fears death," the translation said.

"Purify your heart and clean it from all earthly matters. The time of fun and waste has gone. The time of judgment has arrived. Hence we need to utilize those few hours to ask God for forgiveness. You have to be convinced that those few hours that are left in your life are very few. From there you will begin to live the happy life, the infinite paradise. Be optimistic. The prophet was always optimistic."

The letter became public the same day the F.B.I released photographs of the hijackers and the bureau's director, Robert S. Mueller III said "one or more of them do have contacts with Al Qaeda," the terrorist network linked to Osama bin Laden that is based in Afghanistan.

But Mr. Mueller said that there appeared to be no connection between the 20 or so men who might have fraudulently sought driver's licenses to transport hazardous materials and the 19 hijackers responsible for the Sept. 11 terrorist attacks.

Most of the men are in federal custody, and the authorities say they are still investigating the possibility that the men might have been involved in a separate terrorist plot.

Mr. Mueller, told reporters that many people have been arrested, including several in Pennsylvania, on charges related to efforts to obtain the licenses.

But, Mr. Mueller added, "it is our preliminary belief that those arrests do not relate in any way, or the individuals arrested pursuant to that investigation do not relate, to the occurrences of Sept. 11."

Earlier this week, Attorney General John Ashcroft told a Congressional panel considering his request for expanded law enforcement authority that some of the 20 might have had links to the hijackers. Other law enforcement officials said at the time that this could have meant those involved in planning the Sept. 11 attacks might have ties to people considering other forms of terrorist strikes, including deploying explosives, poisons or other hazardous substances on trucks.

The officials noted that one of the suspected hijackers had also sought information about using light planes for crop-dusting, another suggestion of wider planning.

Although Mr. Mueller said there now appeared to be no connection between the suspected hijackers and those who obtained the hazardous- materials licenses, the authorities were still concerned about why the licenses were sought.

"We are looking at individuals who have obtained hazmat licenses, and particularly those individuals that may have obtained them under suspicious circumstances," Mr. Mueller said, "and we are tracking those leads."

So far, 18 people have been arrested among the 20 that the authorities have said were involved in an effort, centered in Pennsylvania, to obtain the special licenses fraudulently. They were arrested in Pittsburgh and Rockview, Pa., and in Detroit, Seattle, Kansas City, Mo., and Dallas. A few have been released on condition that they remain available to the authorities.

Other law enforcement authorities said it was unclear whether the men arrested in connection with the licenses were contemplating terrorist attacks or were simply participating in a scheme to obtain the licenses without proper credentials to qualify for higher-paid driving assignments.

One official who spoke on the condition of anonymity said that investigators had not ruled out some link to terrorism in connection with the licenses, but that the possibility seemed to be abating in the minds of investigators.

Mr. Mueller and Mr. Ashcroft also released photographs today of the 19 men believed to have been involved in the Sept. 11 hijackings. Mr. Ashcroft said they were issuing the pictures in the hope of prompting recollections across the nation that might provide leads in the investigation.

Since the attacks, senior law enforcement have said that Al Qaeda, the militant Islamic fundamentalist group headed by Osama bin Laden, was behind the attacks.

Today, Mr. Mueller seemed to make the connection more explicit, saying that the evidence showed that one or more of the suspected hijackers had contacts with Mr. bin Laden's group. He would not provide details.

Mr. Ashcroft said the photographs were being released as part of a "national Neighborhood Watch program."

Mr. Mueller said, "These photographs have helped investigators across the nation and, indeed, across the world to uncover information relating to the hijackers."

He asked anyone with information about the men to contact the F.B.I.

But the release of the pictures also demonstrated how difficult the investigation has been. While Mr. Mueller voiced confidence that the identifications of the 19 men were largely accurate, he acknowledged that some might not be.

For 3 of the 19 men, the authorities provided two photographs. In those cases, the photographs are supposed to be different pictures of the same person, but in some cases they do not look alike.

The spellings of several of the names were different from those on the earlier list released by the Justice Department. And Mr. Mueller said it was possible some of the men were using false identities.

"These photographs are photographs that may come from passports, a driver's license obtained in the United States or other identification documents," he said.

The police in Canada, in fact, said today that they might have a lead on how the suspected hijackers obtained false documents.

In one of the parallel investigations around the world, the Canadian police raided three apartments and a photocopy shop this week in and around Toronto that have been linked to a man arrested in Chicago last week in connection with the terrorist attacks.

The police were questioning Ahmad Shehab, who lives in one of the apartments and is the manager of the copy shop. The Toronto Sun reported today that the police were trying to determine whether false identity documents were produced at the copy shop.

Last week, the F.B.I. detained Mr Shehab's nephew, Nabil al-Marabh, in Chicago for questioning about the attacks.

Mr. Marabh, born in Kuwait, was deported to the United States from Canada in 1995 after the immigration authorities rejected his claim for refugee status.

He returned to Canada illegally last year, but was detained by the Canadian authorities at the border crossing at Niagara Falls in June after he was discovered carrying a false passport. The copy shop was closed today, and calls to Mr. Shehab's home went unanswered.