AMBURG, Germany, July 11 — The German police are examining the activities of a former religious leader at a small mosque here who preached murderous hatred of the United States to Mohamed Atta and others who planned and executed the attacks on Sept. 11.
The police and intelligence officials said the imam, whom they know only by his surname, al-Fazazi, preached an unusually heated stream of anti-Western and anti-Jewish abuse at the mosque, called Al Quds. Mr. Atta, the presumed organizer of the attacks and pilot of one of the aircraft that hit the World Trade Center, attended the mosque, as did other members of the Hamburg cell.
The German police have no evidence that Mr. Fazazi was involved in the attacks on Sept. 11. But investigators are intrigued by the number of paths that cross his door. His hate-filled message, the fact that he left Hamburg before Sept. 11 and his ties with people involved in the attacks have all attracted the attention of the German police.
Mr. Fazazi said that "Christians and Jews should have their throats slit" and called on followers to "fight the Americans as long as they are keeping Muslims in prison," according to videotaped sermons seized earlier this month in raids by the Hamburg state police on a bookstore two blocks from the mosque, the police said.
Andreas Croll, a senior antiterrorism officer with the Hamburg state police, said that in the light of the videotapes, "It is fairly easy to make the conclusion after these excerpts that this was a fundamentalist group, and this was the environment that Atta and his roommates were from."
Mr. Fazazi's name has not surfaced previously in the worldwide investigation of the attacks on Sept. 11, and he remains a mysterious figure. German authorities said he was gone before they knew who he was, and American investigators said they had little information about him. It is not known whether Mr. Fazazi ever met with Mr. Atta, or other members of the Hamburg cell, outside the mosque. The plotters are known to have attended the mosque in 1998 and 1999 before Mr. Atta's departure for the United States in 2000.
Mr. Fazazi has not been implicated directly in the attacks or charged with a crime. His exhortation to slit the throats of Americans and Jews would almost certainly be prosecutable under German laws against racist incitement, but German authorities were not aware of his call to murder at the time. Mr. Croll said Mr. Fazazi left Germany, possibly for Morocco, sometime before Sept. 11. He could not be more precise.
Interest in Mr. Fazazi, who is believed to be Moroccan, grew out of raids on July 3 in which the police detained an Atta roommate and six other men thought to be planning new attacks, Mr. Croll said. Videotapes of Mr. Fazazi's sermons were confiscated from a bookstore two blocks from Al Quds mosque as part of the raids.
The police said they believed that the sermons offered a religious justification to the extremists who organized the attacks. Mr. Atta and two other suspected pilots of hijacked aircraft were among five Arabs implicated in the attacks who attended Al Quds.
Like some of the other conspirators, Mr. Atta came to Hamburg as a university student in 1992 and gradually embraced a radical brand of Islam, people who knew him said. Authorities now believe that Mr. Fazazi may have played a role in Mr. Atta's transformation into a suicide pilot, but the stages of Mr. Atta's conversion from student to plotter remain unclear.
The raids in which the sermons were discovered were a result of an innovative computerized profiling technique being used by the Hamburg police to identify hundreds of potential militants, some associated with the Hamburg cell and Osama bin Laden's network, Al Qaeda. There is no evidence that Mr. Fazazi himself had any link to Al Qaeda.
Profiling, or singling out people on the basis of ethnicity, religion or race, is banned in some countries. The practice has raised concern among civil libertarians in the United States who criticized authorities for rounding up 1,200 Muslims after Sept. 11.
But profiling is legal in Germany, and it is playing a major role in the broader investigation by the police in Hamburg and elsewhere.
The scope of the inquiry in Hamburg was conveyed on a large wall chart in a room next to Mr. Croll's office at police headquarters. The chart displayed photographs and names of about 30 Arabs suspected of ties to militants. Red lines diagramed their various connections, with Mr. Atta and his Hamburg apartment at the top of the chart.
Mr. Croll said the police thought Mr. Fazazi was an imam at Al Quds mosque from the late 1990's to at least 2000.
A German intelligence official involved in the investigation said Mr. Fazazi was emerging as a figure in events leading up to the attacks, but he said the religious leader had not come under suspicion before Sept. 11. "We had a general lookout on the mosque, but what he was preaching came to us after he was gone," said the intelligence officer.
German law imposes sharp restrictions on the ability of authorities to investigate religious groups. Even when restrictions were eased after Sept. 11, officials said such monitoring remained difficult. Mr. Fazazi, as an imam, was a public figure, and videotapes of his message were openly on sale until earlier this month. Yet he came to the attention of the German police only after the raids on July 3.
Mr. Fazazi must have been known within Hamburg's Islamic population, but no one wants to talk about him now. Questions about the former imam were met with blank stares at Al Quds mosque and in the cafes and other mosques frequented by Muslim immigrants. Many Muslims here are wary because of the attention from reporters since Sept. 11.
The Attawhid bookstore, where Mr. Fazazi's anti-Western sermons were found, has remained closed since the police raided it on July 3. A sign taped to the window said the store was closed "without justification."
The bookstore owner was among seven men from Morocco, Egypt and Algeria questioned by the Hamburg police after the raids because of suspicions they were planning unspecified new attacks.
One of them, Abdelghani Mzoudi, 29, a Moroccan student, had come to the attention of the police earlier because he shared the apartment where Mr. Atta and two other suspects in the Sept. 11 attacks lived. The police said Mr. Mzoudi attended Al Quds and supported Mr. Atta's group, but he has not been charged with a crime.
The men were identified through the computerized profiling technique introduced in Hamburg after Sept. 11, said Mr. Croll, director of the profiling unit here.
The police in Germany first used profiling in the 1970's to try to find members of the left-wing Red Army Faction, which committed a series of robberies and killings. But, coupled with a toughening of antiterrorism laws, its use against a particular religion has elicited caution this time around.
"We need to pay attention very carefully that, in fighting this form of crime, we do not corrupt ourselves," said Dieter Wiefelsputz, a member of Parliament from the governing Social Democrats. "This is a ride on the razor's edge."
Mr. Croll said the technique played an essential role in discovering potential terrorists in a population of about 120,000 Muslims in Hamburg.
With information about the suspects in the attacks on the United States as a base line, Mr. Croll and his team created a profile of a potential militant. He is a Muslim man, a student age 18 to 40, with legal residence in Germany and origins in a country where religious militancy is rife.
Using data from universities, the central registry of German and foreign residents of Hamburg and other sources, Mr. Croll said the computer program said 811 people matched the profile.
Further analysis of where people lived and with whom they associated narrowed the list of suspects. Among them were the seven men detained on July 3, all of whom attended Al Quds and often met together at the bookstore.
The police monitored their activities and conversations for weeks. They said the men expressed a willingness to die for Islam and discussed plans to travel outside Germany. The police picked them up for questioning though they had not yet discussed concrete plans for attacks.
Three of the men refused to answer questions, and those who did said they were only strong believers, Mr. Croll said. They were released without charges and remain under investigation.