A man accused of plotting to assassinate President Bush was indicted Thursday on additional charges that could bring life in prison, and prosecutors now say he also planned to establish an Al Qaeda (search) cell in the United States.

Prosecutors say Ahmed Omar Abu Ali (search), 24, of Falls Church joined Al Qaeda in 2002 while studying in Saudi Arabia and that he discussed possible terrorist operations, including a plot to kill Bush either by shooting or by a homicide bombing.

Prosecutors also allege Abu Ali discussed plans to assassinate members of Congress and to hijack aircraft and fly them into U.S. targets.

The new indictment adds counts of conspiracy to assassinate the president, conspiracy to commit aircraft piracy and conspiracy to destroy aircraft. Previously, those allegations were included in a general charge of conspiracy to support terrorist organizations.

The aircraft piracy charge carries a mandatory minimum of 20 years in prison and the count alleging assassination conspiracy carries up to life in prison if convicted.

Abu Ali has denied the charges and says he was tortured into a false confession by Saudi authorities working with the United States.

Prosecutors deny Abu Ali was mistreated in Saudi custody.

Thursday's indictment includes new details, including an alleged plan to smuggle Saudi Al Qaeda members into the United States through Mexico, where they would join Abu Ali as part of an Al Qaeda cell dedicated to terrorist acts.

Previously, prosecutors had only said Abu Ali wanted to be a planner of terrorist attacks in the mold of Sept. 11 (search) mastermind Mohammed Atta (search).

According to the indictment, Abu Ali also guarded an Al Qaeda safe house in Saudi Arabia (search) in May 2003 and translated materials from English to Arabic for Al Qaeda.

Abu Ali was arrested by the Saudis in June 2003 and held for nearly two years before he was brought back to the United States in February to face charges.

His trial is set for October, and prosecutors don't expect the new indictment to delay it. His arraignment on the new charges is expected next week.

A pretrial hearing is scheduled for Sept. 19 to address Abu Ali's claims that he was tortured and that he was arrested by Saudis at the behest of the United States. If U.S. District Judge Gerald Bruce Lee rules in favor of Abu Ali on either of those claims, he could dismiss all charges.

Prosecutors filed a motion Thursday asking the judge to bar testimony from two doctors who concluded Abu Ali was tortured. Assistant U.S. Attorney David Laufman said defense lawyers failed to turn over the doctors' reports by a court-imposed deadline, making it impossible for prosecutors' experts to fully review them.

Abu Ali's lawyer, Khurrum Wahid, did not immediately return calls seeking comment Thursday.