Another person has been added to the list of terrorism suspects that the United States is classifying as enemy combatants and subject to facing a military tribunal. The Justice Department says the suspect, from Qatar, may have been involved in planning more attacks against the United States.

Ali Saleh Kahlah al-Marri arrived in the United States the day before the September 11 terrorist attacks two years ago, and was indicted for making false statements in connection with the New York and Washington attacks.

But for reasons of national security, President Bush Monday designated him as an enemy combatant. That means he no longer faces trial in criminal court, but could possibly face trial a military tribunal with far fewer legal rights than he would have as a criminal defendant.

The decision to hand the 37-year-old over to the custody of the Pentagon came as the Justice Department announced that a suspect already detained in on-going anti-terrorism operations, identified Mr. al-Marri as an al-Qaida operative and someone who was allegedly helping al-Qaida sleeper cells in the United States organize more possible attacks.

Hundreds of enemy combatants are being held by the United States at a base in Cuba, but this marks only the third time U.S. authorities have identified one by name. The two others, both American citizens, are Yaser Hamdi, a Louisiana native captured in Afghanistan, and Jose Padilla, who is alleged to have been involved in a plot to detonate a radioactive bomb in the United States.