"Sadly, today we learned of the death of our colleague, Burhan Muhammad Mazhur," ABC News President David Westin said in a statement on Friday.
"An Iraqi citizen, Burhan had been working as a freelance cameraman for ABC News in Falluja for about two months. He died of gunshot wounds while covering a firefight in Falluja."
"We are trying to confirm all the details surrounding his death and have asked the US military for an investigation. We will miss Burhan's dedication and professionalism. Our thoughts and prayers are with his family," Westin said.
Mazhur was shot in the head and taken to Falluja hospital, where he died shortly afterwards. Witnesses said US occupation troops fired at him. The US military said it had no information about the incident.
New York-based Time magazine on Friday said an Iraqi translator it employed in Baghdad had died after being shot earlier in the week.
Last week, two Iraqi journalists working for Dubai-based satellite news channel al-Arabiya were shot and killed in their car in Baghdad. al-Arabiya said they were killed by US troops at a checkpoint. The US army said it was still investigating.
Before that incident, four journalists had been killed by US troops since the start of the war in Iraq a year ago.
Journalists in Iraq protest killings
Reuters cameraman Taras Protsyuk, a Ukranian, and cameraman Jose Couso of Spanish television channel Tele 5, were killed on 8 April last year when a US tank fired a shell at Baghdad's Palestine hotel, where most foreign media in the city were staying during the US-led invasion.
Tarek Ayoub, a producer and correspondent for Aljazeera, was killed in a US air raid in Baghdad the same day.
On 17 August, award-winning Reuters cameraman Mazen Dana, a Palestinian, was shot dead by a US soldier outside Abu Ghraib prison west of Baghdad.
The US army said the soldier mistook Dana's camera for a rocket-propelled grenade launcher.
A number of media employees have been killed in Iraq in recent weeks. Some have been targeted by fighters resisting the occupation, who have increasingly focussed on "soft targets", including Iraqis working for Western companies.
Last week, armed men ambushed and killed three Iraqis working for a US-funded television and radio station near Baquba, northeast of Baghdad.
Earlier this month, a translator working for Voice of America was shot and killed in his car along with his mother and daughter in an apparently targeted attack.
In January, armed men opened fire on a CNN convoy south of Baghdad, killing two Iraqi staff.