KABUL, July 24: Further vigilante groups are operating in Afghanistan like the three US citizens facing trial for setting up a private prison in Kabul, a US military spokesman said on Saturday.

But the example of Jonathan K. Idema and two other US nationals, who were arrested earlier this month, would help coalition and Afghan authorities to spot and crack down on similar acts in future.

"There are others acting independently," military spokesman Major Jon Siepmann said after being asked if similar groups could be operating in the war-shattered country.

"However I think the issue of Mr Idema brought to high awareness to every one involved, the government, the coalition forces to be and look out for the sort of behaviour," he told a news briefing in Kabul.

Siepmann added: "I think Mr Idema's arrest and current judicial process will serve as a warning to others who attempt to do this in Afghanistan."

Idema, Brent Bennett and Edward Caraballo stand charged with running a jail where they allegedly tortured eight Afghans without the permission of the Afghan or US authorities.

On Wednesday, Idema told an Afghan court hearing that he worked with the full knowledge of US State Department officials including State Secretary Donald Rumsfeld.

He said that he had detained the Taliban intelligence chief in the eastern Afghan city of Jalalabad and passed him to US-led coalition for questioning.

The coalition on Thursday admitted they had taken a detainee from Idema and his group, but denied he had been working for the US military.

The US State Department and the military in Afghanistan had previously issued repeated denials that Idema had any ties with the US government or military.

"Firstly we receive detainees from a variety of sources," Siepmann said of coalition strategy of war on terror. "Generally we are interested in taking a Taliban or other terrorist out of Afghanistan so any one who turns over someone on our list we are going to accept them."

The case appeared as another scandal and an embarrassment for US forces, already under fire from rights groups for alleged mistreatment of detainees in Afghanistan and Iraq.

Afghanistan's capital Kabul is being patrolled by more than 7,000 members of a Nato-led peacekeeping force. Hundreds of coalition Special Forces move around in plain clothes and it is hard for the locals to distinguish them.-AFP