GUANTANAMO BAY NAVAL BASE, Cuba - An Afghan detainee said Wednesday that he wants to boycott his trial at Guantanamo Bay and railed against the proceedings as unfair and illegal.

Mohammed Jawad, who is accused of throwing a grenade that wounded two U.S. soldiers, initially refused to attend his first pretrial hearing, delaying its start. After he appeared in the courtroom, the judge, Marine Col. Ralph Kohlmann, warned Jawad that if he does not attend future sessions he could still be tried, convicted and sentenced in absentia.

In combative exchanges with the judge, Jawad said he has been mistreated at Guantanamo Bay -- where the U.S. military holds about 275 men suspected of links to al Qaeda and the Taliban -- and denounced the tribunal system as unjust.

"I am innocent, I want justice and fairness," said Jawad, who spoke through a Pashto translator and asked the judge whether journalists could hear his statements. "Since I was arrested I've been treated unfairly. I have been tortured. I am a human being."

The only specifics he offered were that he's had a "bleeding lip" for more than a year and he said he suffers from constant headaches from the bright lights in his prison cell.

Jawad, who wore the orange uniform reserved for the least compliant detainees, later slammed down his translation headphones and put his head down on the desk.

He did not enter a plea to charges of attempted murder and intentionally causing serious bodily injury, which could lead to a maximum sentence of life in prison.

The hearing inside the hilltop courthouse overlooking the Caribbean was delayed more than two and a half hours after Jawad initially refused to attend. Kohlmann ordered his ankles to remain shackled during the hearing because he was not cooperating fully.

The judge also excused Jawad's Pentagon-appointed defense attorney, Army Col. James Sawyers, who asked to be removed from the case because he is leaving active-duty service. He said the effort to find a replacement could cause a delay in bringing the case to trial.

Jawad said he was 16 when he was arrested and did not understand some of the rules the judge explained to him.

He is accused of throwing a homemade hand grenade into a jeep carrying two U.S. soldiers and their interpreter in Kabul, the Afghan capital, in 2002. The three were wounded.

In a phone interview, one of those wounded in the attack, former Army Sgt. 1st Class Christopher Martin, said he should never be let out of U.S. military custody.

Even if Jawad goes to trial and is found innocent, Martin may still get his wish. The U.S. military retains the right to hold indefinitely those considered to pose a threat to the United States -- even those who have been cleared of charges at Guantanamo's "military commissions."

Martin, a U.S. National Guard soldier, arrived in Afghanistan in October 2002 with a Special Forces unit assigned to train a new national army. Near sunset on Dec. 17, he and Army Sgt. 1st Class Michael Lyons were moving slowly in a jeep amid a stream of cars, trucks and ox carts, with Lyons driving and Martin in the front passenger seat. Their interpreter was in the back seat.

A grenade suddenly came in through the rear window, which was missing its glass, and landed at the soldiers' feet.

It exploded, engulfing the jeep in flames and sending shrapnel into the two Americans. The translator, who was in the back seat, was only slightly wounded.

Martin said he commandeered a taxi and he and bystanders moved Lyons from the jeep. Before leaving to seek first aid, Martin saw two Afghan policemen in the crowd grab a teenager in a robe. He was carrying two other grenades.

"It is believed that he was going to finish us off with the other two," Martin said.

The attack left Martin with broken bones in both feet, a punctured ear drum and an eye injury that has required a half dozen surgeries. He resumed working for the Long Beach police after more than 18 months of rehabilitation, but still has a limp from nerve damage in a leg.

Lyons returned to active-duty service after recovering from injuries to the lower half of his body, Martin said.

The military plans to prosecute about 80 of the roughly 275 prisoners held at this U.S. base in southeast Cuba on suspicion of links to al Qaeda or the Taliban. So far, roughly a dozen have been charged and none of the cases has gone to trial.