A US Marine transport helicopter crashed in flames in a field northwest of Baghdad, killing all seven people aboard, the US military said. It was the fifth US aircraft lost in less than three weeks and the latest sign of growing problems with aviation in Iraq.
A US military statement gave no reason for the crash of the CH-46 Sea Knight, which went down on Wednesday near Fallujah in Anbar Province, about 30km from Baghdad. However, at the Pentagon, three Marine Corps officials said the troop-transport helicopter was in flames when it went down, with the pilot appearing to attempt a hasty landing but losing control as the aircraft descended.
They said witnesses in nearby Marine aircraft saw the flames but saw no sign that it involved hostile fire.
An Iraqi air force officer, however, said the helicopter was downed by an anti-aircraft missile. He spoke on condition of anonymity because he was not authorized to release information.
An Iraqi farmer who lives about a kilometer from the crash site said he heard a missile fired moments before the crash, which took place in an insurgent-infested region.
"The helicopter was flying and passed over us, then we heard the firing of a missile," the farmer, Mohammed al-Janabi, said. "The helicopter then turned into a ball of fire. It flew in a circle twice and then went down."
Associated Press Television video showed the flaming wreckage lying in a field in front of a cluster of mud homes. A dense plume of black smoke rose over the remains. The Marine officials suspected the fire was caused by a mechanical problem, the officials said. They spoke on condition of anonymity because the investigation was ongoing.
Names of the victims were not released, but military officials said they included five Marines and two from the Navy.
In a statement posted on an extremist Web site, an al-Qaeda-linked group, the Islamic State in Iraq, claimed it shot down the helicopter, which it described as a Chinook -- an Army helicopter which resembles a Sea Knight.
Critics have long urged the military to replace the CH-46, which was introduced in 1964 at the start of the Vietnam War. In 2001, retired Colonel Frank Jensen wrote in Defense News that the Marines should replace the CH-46 but cannot because of budget limitations.
Regardless of the cause, the latest crash adds urgency to a US military review of flight operations in Iraq, including whether insurgents have perfected skills in attacking US planes.
The latest crash occurred five days after a US Army Apache helicopter went down in a hail of gunfire north of Baghdad. Three other helicopters -- two from the Army and one operated by a US security firm -- have also crashed since Jan. 20. A total of 27 people -- 23 US service members and four US civilian contractors -- were killed in those five crashes.
The military did not say whether all seven killed in Wednesday's crash were Americans, but it was likely that they were.