BAGHDAD – The U.S. military freed a Reuters television cameraman on Thursday after holding him for three weeks in Iraq without charges.

Ali al-Mashhadani, who also works freelance for the BBC and Washington-based National Public Radio, was detained in Baghdad on July 30 while he was in the Green Zone government compound for routine checks for a U.S. military press card.

U.S. forces have detained Mashhadani twice before, at one point holding him for five months, but no charge has ever been filed against the cameraman, who is based in Ramadi, the capital of western Anbar province.

The U.S. military said at the time of his latest arrest that he was held 'because he has been assessed to be a threat to the security of Iraq and coalition forces,' but did not elaborate.

Reuters Editor-in-Chief David Schlesinger said he was pleased Mashhadani was released but concerned that it was the third time he was 'detained without explanation'.

'If there are legitimate issues about him or any other journalist, let's have them aired openly and tested. If there are none, let them pursue their profession free from intimidation and fear.'

Mashhadani's other employers expressed similar concerns.

NPR's senior foreign editor, Loren Jenkins, said: 'I'm delighted that Ali has finally been released and that it turns out there was no basis for his detention. But I remain concerned that such actions can be taken against a working journalist with their reasons never being explained or justified.'

Jon Williams, BBC News world editor, said: 'Ali is part of our Iraqi family – his colleagues in London and Baghdad are delighted he's been freed. We now look to the American military authorities to offer evidence and an explanation for Ali's detention.'

U.S. military spokesman Rear Admiral Patrick Driscoll said he was preparing a response to questions posed by Reuters.

The military says that under the U.N. mandate governing the presence of foreign forces in Iraq it can detain anyone considered a security risk indefinitely.

U.S. forces previously detained Mashhadani in August 2005 after troops became suspicious of film they found on his cameras while searching his home in Ramadi. He was freed in January 2006, then detained again for two weeks in mid-2006.

The manner of Mashhadani's latest arrest was unusual, as he was inside the heavily-guarded press center in the Green Zone compound. To get there, he would have had his identity checked and been searched at a series of entry checkpoints.

Two Iraqi journalists who were in the military press office when he was detained said U.S. soldiers suddenly appeared, frisked him and led him away. Two other witnesses said they saw soldiers escorting a handcuffed man with a hood over his head.

U.S. forces have held other Iraqi reporters working for Reuters and journalists from different media groups for long periods without charging them. In April, the U.S. military freed a Pulitzer Prize-winning Iraqi photographer working for the Associated Press after holding him without charge for two years.