In a special report based on interviews with a dozen reporters who were at the scene, the CPJ urged the Pentagon to conduct a "thorough and public investigation" into the April 8 incident.

"Such a public accounting is necessary, not only to determine the causes of this incident, but also to ensure that similar episodes to not occur in the future," the report said.

Ukranian-born Reuters cameraman Taras Protsyuk and Spanish cameraman Jose Couso of Telecino were fatally wounded when a US Abrams tank fired a single round at the Palestine Hotel during heavy fighting in Baghdad.

Three other journalists were injured in the attack on the hotel, where around 100 international journalists were staying at the time.

CPJ said its own investigations suggested that the attack, "while not deliberate, was avoidable."

The lobby group said it had learned that Pentagon officials, as well as commanders on the ground in Baghdad, knew that the Palestine Hotel was full of international journalists and were intent on not hitting the building.

"However, these senior officers apparently failed to convey their concern to the tank commander who fired on the hotel," the report said.

In the aftermath of the attack, U.S. military officials gave a variety of explanations for the shelling of the Palestine Hotel, mainly alleging that US forces had come under "significant" enemy fire from the hotel.

That version of events was challenged by the CPJ report.

"There is simply no evidence to support the official US position that US forces were returning hostile fire from the Palestine Hotel," it said. "It conflicts with eyewitness testimonies of numerous journalists in the hotel."

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