A Pakistan-born student awaiting trial on terror charges must remain in solitary confinement, under conditions reserved for the most dangerous inmates, a judge ruled Friday.

Judge Loretta A. Preska rejected Syed Hashmi's request to have his prison conditions relaxed. The judge cited the seriousness of the charges against Hashmi and an encounter he had last summer with guards when he was practicing martial arts in his cell at a federal jail in New York.

Lifting the restrictions would pose a threat to guards, Preska said.

Hashmi, 28, a U.S. citizen born in Pakistan, was arrested in London in June 2006 and extradited to the United States a year later on charges of conspiracy to aid a terrorist group. He has pleaded not guilty.

If convicted, he could face up to 70 years in prison.

Prosecutors say Hashmi stored luggage full of raincoats, ponchos and waterproof socks in his London apartment in 2004 for an acquaintance. The acquaintance later gave the items to a high-ranking al-Qaida member for the group's use in fighting U.S. forces in Afghanistan, according to prosecutors. Hashmi has said he knew nothing of any militant schemes.

The government has argued that Hashmi must be kept isolated so he doesn't communicate dangerous messages to others.

Prosecutors say guards reported seeing Hashmi practicing what appeared to be martial arts in his cell last August and telling Bureau of Prisons officials, "I am practicing for you guys." Hashmi has disputed the account in a written statement, saying he was only exercising, according to prosecutors.

His lawyer, Sean M. Maher, did not immediately return a telephone call Friday.

During a hearing earlier Friday, Maher presented psychiatric reports saying the isolation was psychologically harmful to his client.

Under his special prison conditions, Hashmi cannot communicate, share a cell or worship with fellow inmates. Any newspapers are delivered with a 30-day delay. He is not permitted to listen to radio or television news programs, and only his attorneys and close relatives can visit him.

"I believe we can predict with certainty Mr. Hashmi is going to be psychologically, emotionally damaged because of the lockdown," Maher said.

Hashmi moved with his family to the United States when he was 3. He grew up in the New York City borough of Queens before graduating from Brooklyn College in 2003. He later moved to London to study for a master's degree in international relations at the London Metropolitan University.

Last year, more than 550 academics from across the country signed a petition saying they believed Hashmi's pretrial detention conditions were a threat to his right to a fair trial, Maher noted.