Eyewitnesses said US soldiers on a tank shot Dana, 43, as he was filming outside the Abu Ghraib prison in western Baghdad.
His last footage shows a US tank driving towards him as he filmed outside the prison walls. Several shots ring out from the tank and Dana’s camera falls to the ground.
US military officials admitted that its troops had “engaged” Dana, a father of four, saying they had thought his camera was a rocket-propelled grenade launcher.
“Army soldiers engaged an individual they thought was aiming an RPG at them. It turned out to be a Reuters cameraman," Navy Captain Frank Thorp, a spokesman for the chairman of the joint chiefs of staff, told Reuters in Washington.
The killing took place in broad daylight.
Occupation officials in Iraq said an investigation into the incident was underway.
Journalists had gone to the prison after the US military said a mortar bomb attack there a day before had killed 6 Iraqis and wounded 59 others.
Recounting the moments before the shooting, Reuters soundman Nael al-Shyoukhi, who was working with Dana, said he had asked a US soldier near the prison if they could speak to an officer and was told they could not.
"Mazen took a last breath and died before my eyes"
Nael al-Shyoukhi, Reuters soundman
“They saw us and they knew about our identities and our mission,” he said. A soldier agreed to allow them to film an overview from a bridge nearby.
“After we filmed we went into the car and prepared to go when a convoy led by a tank arrived and Mazen stepped out of the car to film. I followed him and Mazen walked three to four metres,” said al-Shyoukhi.
“A soldier on the tank shot at us. I lay on the ground. I heard Mazen and I saw him scream and touching his chest.
“I cried at the soldier, telling him you killed a journalist. They shouted at me and asked me to step back and I said, ‘ I will step back but please help, please help and stop the bleed.’”
“They tried to help him but Mazen bled heavily. Mazen took a last breath and died before my eyes.”
"King of Hebron"
Dana protests for a halt to Israeli
army's killing of journalists
“Mazen was one of Reuters finest cameramen and we are devastated by his loss,” said Stephen Jukes, Reuters global head of news.
Dana, a Palestinian, had worked for Reuters mainly in the occupied West Bank city of Hebron.
Paul Holmes, former Reuters bureau chief in Jerusalem, recalled a towering, chain-smoking bear of a man with a ruddy complexion and expansive heart.
“The amazing thing about him was he was like the king of Hebron. Every journalist in the city looked up to him and any journalist who covered the Israeli-Palestinian conflict will know and love Mazen," he said.
Dana was awarded an International Press Freedom Award in 2001 by the Committee to Protect Journalists for his work in Hebron where he was beaten and wounded many times.
Dana’s death brings to 17 the number of journalists or their assistants killed in Iraq since the Washington-London attack against the country on 20 March.
Dana is the second Reuters cameraman to be killed. On 8 April, Taras Protsyuk was killed when a US tank fired a shell at the 15th floor of the Palestine Hotel, a well-known base for journalists covering the war.