A Yemeni American man acknowledged that he met al Qaeda leader Osama bin Laden in Afghanistan in 2001 as he pleaded guilty today to charges of supporting the militant Islamic network.

Sahim Alwan was the fourth of six U.S. citizens of Yemeni descent to reach a plea agreement with the government on charges that they were part of an al Qaeda "sleeper cell" operating in the United States, but he was the only one who told investigators that he had met bin Laden.

Alwan, 30, admitted in U.S. District Court in Buffalo that he provided "material support" to al Qaeda by attending the al Farooq training camp and by receiving weapons training there.

The six, who are from the steel town of Lackawanna, near Buffalo, were arrested in September on charges that they had attended an al Qaeda training camp near Kandahar, Afghanistan, in April 2001. They initially pleaded not guilty.

None was accused of involvement in the Sept. 11, 2001, attacks in New York and on the Pentagon or in other acts of violence believed to have been masterminded by bin Laden.

In October, Alwan, a job counselor, was the only one of the six suspects granted bail, largely because he had cooperated with the FBI from the early stages of the investigation. But the conditions for bail were strict and included house arrest.