Three Americans accused of detaining and abusing Afghans on an independent hunt for terrorists appeared in court Sunday, insisting they had contacts with the U.S. Defense Department (search), while acknowledging that they ran an illegal jail, a judge said.

The trio, led by a former soldier named Jonathan K. Idema (search), and four Afghans face charges of hostage-taking and assault over the detention of 11 men in a house in the capital. They could be jailed for up to 20 years if convicted.

U.S. and Afghan authorities deny any links to the men, describing them as freelance vigilantes on a personal mission to fight terrorism. The men wore military fatigues and were able to fool both Afghan police and NATO (search) peacekeepers into thinking they were legitimate.

Afghan security forces raided the makeshift prison and arrested the seven defendants on July 5 after peacekeepers realized they were impostors.

Appearing at a preliminary hearing at Kabul's lower court, Idema insisted that an Associated Press Television News reporter stop making videotape of him.

"Bin Laden has half a million dollars on my head," Idema shouted, standing next to his comrades in a khaki military uniform with a patch of tape covering the insignia on the shoulders.

The reporter was asked to leave the court.

Abdul Baset Bakhtyari, the presiding judge, told AP later that the hearing was called to tell the defendants to prepare their defense for a full trial next week.

The judge also gave new details of the charges against them, including alleged abuse of detainees.

"There is evidence that they tied their hands, hooded them and poured cold or boiling water over them during interrogations," Bakhtyari said.

He had no information on allegations that Afghan forces found several of the prisoners hanging from their feet when they raided the illegal jail.

The issue has been a sensitive one. The U.S. military is embroiled in a widening investigation over the deaths of several Afghan detainees while in American custody.

The defendants acknowledged that they had acted illegally, while insisting their only goal was to "struggle against terrorism," Bakhtyari said.

"They said they were a nongovernment group but that they had private contact with the Pentagon," Bakhtyari said. He said the three gave no details. "They couldn't provide any evidence."

It remains unclear whether the defendants had picked up innocent Afghans of were on the trail of genuine militants.

NATO bomb-disposal teams found traces of explosives in two houses raided by Idema's group, the force has said.

Bakhtyari acknowledged that several of those found in the illegal jail are still being held by Afghan authorities "to get some additional information." He said they would be released shortly.