LONDON (Reuters) Media rights groups demanded on Thursday that U.S. forces immediately release a Reuters journalist held in Abu Ghraib prison in Iraq unless they could explain why he is being held without charge.

Reporters Without Borders, a Paris-based organisation that campaigns to protect journalists detained or threatened because of their work, said it had written to top U.S. Middle East commander General John Abizaid to demand the release of 36-year-old Ali Omar Abrahem al-Mashhadani.

It also accused U.S. forces of carrying out summary arrests of journalists in Iraq without providing any justification.

"We point out that the decision to arrest a journalist should only be taken on an absolutely exceptional basis," the organisation said.

"Journalists, especially Iraqi journalists, are already running very great risks to go into the field. More than 60 have already lost their lives in this country in two years. It is shocking that they are also being mistreated by the U.S. army."

The New York-based Committee to Protect Journalists also urged the release of Mashhadani, unless the U.S. military could offer an explanation for his detention.

"U.S. officials must credibly explain the basis for the detention of Ali Omar Abrahem al-Mashhadani and other journalists being held without charge, or release them at once," CPJ Executive Director Ann Cooper said.

"U.S. forces continue these alarming detentions of working journalists without any acceptable explanation, or anything resembling due process," she said.

"We believe our colleagues are being detained for merely carrying out their professional work. These long-term detentions by the U.S. military are a further unacceptable curb on journalists who already operate under near-impossible conditions in the field in Iraq."

U.S. military spokesmen have refused to say why they are holding Mashhadani, 36, who has worked for Reuters for a year as a freelance cameraman and photographer in the city of Ramadi.

Lieutenant Colonel Guy Rudisill, spokesman for U.S. detainee operations in Iraq, said the journalist was in Abu Ghraib prison and would not be allowed visitors for 60 days.

Reuters has demanded that the military release Mashhadani or provide a full account of the accusations against him.

An account from Mashhadani's family of his arrest on Aug. 8 suggests that images found by U.S. Marines on his cameras during a general sweep in the neighbourhood prompted his detention.

Relatives said that Marines conducting a routine search of the house turned hostile after viewing images stored on Mashhadani's video and stills cameras and his desktop computer.

Reuters has provided U.S. forces with footage by Mashhadani that shows scenes of conflict and gunmen operating in plain view of civilians. Nothing in his work has indicated activity incompatible with his status as an independent journalist.

U.S. military officials have responded neither to offers of further information from Reuters nor to proposals for meetings with Reuters editors to clarify Mashhadani's activities.

Journalists for Reuters and other media organisations in Iraq have been wrongly accused in the past by U.S. forces of having prior information of insurgent attacks -- suspicions apparently raised by their quick response to news events.

"U.S. and Iraqi military forces routinely detain Iraqi journalists without charge or explanation, and some have been held for months," the CPJ said. It said it had raised concerns in May about eight Iraqi journalists in detention in Iraq, including local staff for CBS News and Agence France Press.

Reporters Without Borders said the arrest and detention of Iraqi journalists "does not reflect well on the United States, which nonetheless does not hesitate to give the rest of the world lessons on freedom of expression and democracy."
Andrew Marshall, Reuters (letters@editorandpublisher.com)

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