Firing their guns in the air, the dozen odd policemen, some masked, stormed into the rooms of journalists in the Najaf Sea hotel and forced them into vans and a truck.
An AFP correspondent, who was also forced into a van, said the police pushed and pulled many reporters at gunpoint.
After a two-minute drive from the hotel, where journalists from across the world are based while covering the battle between al-Mahdi Army militiamen and US occupation forces city, the reporters were taken to the office of the police chief.
"You people are not under arrest," Najaf police chief Ghalib al-Jezari told them.
"You are brought here because I want to tell you that you never publish the truth. I speak the truth, but you never broadcast what we are."
The reporters, packed into the office, with some sitting on the floor in front of the police chief, protested at their detention.
"You have kidnapped us at gunpoint," said one reporter.
The police chief complained that reporters have been misreporting the proposed visit to Najaf by Grand Ayatollah Ali al-Sistani, the revered Iraqi Shiite Muslim leader.
Arab media detained
Iraqi police also arrested five members of a Dubai-based television news crew after they reported that US planes had fired missiles within metres of the Imam Ali mausoleum.
An Al-Arabiya satellite news bulletin on Wednesday evening said that although no official reason had been given, their detention came within minutes of a 17:00 GMT broadcast with live coverage of seriously fierce fighting in Najaf.
Damage to the Imam Ali complex, already the scene of major resistance to US occupation forces, would almost certainly exacerbate the conflict.
Iraqi security officials arrested the TV crew at their hotel in Najaf, taking five members into custody - including Iraq correspondent Diyar al-Omari.
Iran expects release
The arrests came as Iran's IRNA new agency announced it hopes to see two or three of its journalists released after their detention in Iraq on 9 August.
A source close to Iraqi Prime Minister Iyad Allawi was quoted as saying two of the three IRNA journalists would be released, but did not say which ones.
IRNA's Baghdad bureau chief Mustafa Darban, and colleagues Muhammad Khafaji and Muhsin Madani went initially feared kidnapped before Tehran announced all three had been arrested by Iraqi police.