German 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. 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...