erman investigators say they have evidence that Mohamed Atta, the suspected ringleader of the Sept. 11 attacks, and two accomplices trained at Qaeda camps in Afghanistan from late 1999 to early 2000. They have also established a clear link between Al Qaeda and a recent attack on a Tunisian synagogue, a top official said.

Advertisement

The timing of the Afghanistan training, outlined yesterday by a senior investigator, provides the strongest evidence so far that plans for the attacks on the United States were worked out there. Less than six months after leaving Afghanistan, Mr. Atta and the other two men enrolled in flight schools in the United States.

There have been previous reports that Mr. Atta and other conspirators trained in Afghanistan, and F.B.I. officials have said privately that all 19 hijackers are believed to have spent time there. But the investigator, Klaus Ulrich Kersten, director of Germany's federal anticrime agency, the Bundeskriminalamt, provided the first official confirmation that the three pilots had been in Afghanistan and the first dates of the training.

Mr. Kersten said in an interview at the agency's headquarters in Wiesbaden, Germany, that Mr. Atta was in Afghanistan from late 1999 until early 2000. He said four other Arabs from Hamburg attended camps there about the same time. Two of them, Marwan al-Shehhi and Ziad al-Jarrah, also flew hijacked planes on Sept. 11. The two others, Said Bahaji and Ramzi bin al-Shibh, both disappeared shortly before the attacks and have been charged in Germany as accomplices.

"According to our knowledge, Atta traveled to Afghanistan for some months in 1999 until early 2000," Mr. Kersten said. "Whether he had been there before, we do not know. We know that Jarrah, Shehhi, bin al Shibh and Bahaji were also in Afghanistan in the same time period, but we do not know if they were together."

Mr. Atta, Mr. Shehhi and Mr. Jarrah came to the United States in June 2000 and enrolled in flight schools in Florida. Mr. Atta and Mr. Shehhi are believed to have piloted the two hijacked airliners that hit the World Trade Center towers, and Mr. Jarrah flew the plane that crashed in the Pennsylvania countryside.

Mr. Kersten, the top official in Germany's equivalent of the F.B.I., also indicated that Al Qaeda was still operating. He said a Qaeda leader identified by the American authorities as a key planner of the Sept. 11 attacks was phoned by a suicide bomber three hours before the bomber set off a blast outside a synagogue in Djerba, Tunisia, in April that killed 21 people.

Mr. Kersten said the suicide bomber had telephoned the Qaeda contact, Khalid Shaikh Mohammed, a 37-year-old Kuwaiti identified by the American authorities in June as having played an important operational role in the Sept. 11 attacks.

Mr. Kersten said the bomber, Nizar Nawar, called the Kuwaiti, who is believed to be hiding in Pakistan, shortly before Mr. Nawar pulled up outside the synagogue in a truck. The vehicle was filled with liquid propane, and Mr. Nawar ignited an explosion that killed 14 German tourists, 6 Tunisians and a Frenchman, in addition to himself.

"There are indications that this attack in Djerba was perpetrated with the blessing or approval of Al Qaeda," he said. "We can say Sept. 11 and Djerba with certainty were Qaeda."

Mr. Mohammed, the Kuwaiti, may be the link between Sept. 11 and other Qaeda plots. The American authorities said intelligence reports placed him in Germany in 1999, when Mr. Atta and others lived there.

He may also be tied to the bombing of the World Trade Center in 1993, and he has been charged in a plot to blow up as many as 12 American jetliners over the Pacific in 1995. The American authorities said Mr. Mohammed might be a relative of Ramzi Ahmed Yousef, the leader of the group that carried out the 1993 bombing.

In the interview in Wiesbaden, Mr. Kersten acknowledged that substantial amounts of the planning for the Sept. 11 attacks had occurred in Germany. But he said the authorities now had evidence that the plot originated with top Qaeda leaders in Afghanistan.

"We know that the initial decision to carry out a terrorist act came from Afghanistan," he said, "more specifically, from the top Qaeda leadership. We believe, too, that there were then further phases when the plans were made more precise, not only in Germany, and involving many other people."

Mr. Kersten did not identify any new suspects or specify how many other people might have been involved. French antiterrorism officials said in interviews last month that the Sept. 11 plotters were probably assisted by many other people in Europe and the United States, though few arrests have been made.

The investigator also said Al Qaeda was planning new attacks, though he said the authorities knew of no specific plots.

"The threat still exists, and it is as great as before," he said. "There is no decline in action, and there are indications of new plans. Al Qaeda is not defeated, maybe weakened."

Mr. Kersten also shed light on a crucial planning meeting for Sept. 11 that was held in January 2000 in Kuala Lumpur, Malaysia. American intelligence officials learned of the meeting before it took place, and Malaysian security agents monitored it at their request.

Mr. Kersten said there were new indications that Mr. Shibh, one of the suspected Hamburg plotters, had attended that meeting. He declined to describe the evidence, but said it went beyond a photograph that has surfaced of an attendee whom some people have identified as Mr. Shibh.

"There are indications that Ramzi bin al-Shibh was in Kuala Lumpur for the meeting," he said.

Mr. Shibh's presence would connect the Hamburg group to two other hijackers, Khalid al-Midhar and Nawaq Alhazmi, who have been identified positively as having taken part in the Kuala Lumpur meeting.

Mr. Midhar and Mr. Alhazmi were on the hijacked aircraft that crashed into the Pentagon. They had entered the United States a few days after the Kuala Lumpur meeting through Los Angeles, unlike the members of the Hamburg group, who flew into East Coast cities.