The official said that the men were arrested after investigators learned that they had traveled to Afghanistan and received training at Qaeda camps.
The government says he trained at a Qaeda camp in Afghanistan for about a year and a half between 1996 and 1998, specializing in poisons.
But once in Pakistan, the men went on to take military training at a Qaeda camp in Afghanistan, investigators say.
Most of the members of the regional terror groups trained at the Qaeda camps, counterterrorism officials say.
The groups are actively recruiting young men, who were not necessarily trained in Qaeda camps in Afghanistan, the officials said.
Some F.B.I. officials say they were especially worried about the Qaeda camps, and what their graduates planned to do.
And, the judge said, the evidence of the young men's presence at the Qaeda camp in Afghanistan raised several questions: Were they recruited?
Under interrogation, he has admitted to traveling five times to Qaeda camps in Afghanistan, including once about a month after the Sept. 11 attacks.
According to Australian intelligence, he went to Afghanistan and entered Qaeda camps.
Just about everyone in Kandahar and the Qaeda camps knew that something big was coming, he said.