A preliminary military inquiry found evidence that US Marines killed two dozen Iraqi civilians in an unprovoked attack in November, contradicting the troops' account, US officials said today.
Forensic evidence from corpses showed that victims had bullet wounds, despite the initial statements by Marines that the civilians were killed by a roadside bomb that also claimed the life of a soldier, a defense official said.
"The forensics painted a different story than what the Marines had said," said the official, speaking on condition of anonymity due to the sensitivity of the matter.
The official said the bodies had wounds that would not have been caused by an improvised explosive device.
President George W Bush said today there would be punishment if an investigation turns up evidence of wrongdoing by US Marines in the killings in the Iraqi town of Haditha.
"I am troubled by the initial news stories," Mr Bush said. "I am mindful there is a thorough investigation going on. If in fact laws were broken there will be punishment."
Residents of Haditha, 125 miles (200 km) northwest of Baghdad in an area that has seen much activity by Sunni Arab insurgents, have said that US Marines attacked houses and shot people after their patrol was hit by a roadside bomb.
It could be the worst known case of abuse by US soldiers since the 2003 invasion and comes at a time when public opinion polls show falling US public support for the war.
There are two investigations into the matter -- a criminal probe that might lead to murder charges against Marines and another investigation into whether Marines tried to cover up the true nature of the incident, officials said.
Earlier Iraq's prime minister has said his patience was wearing thin with excuses from US troops that they kill civilians by "mistake" and said he would launch an investigation into killings at Haditha last year.
"There is a limit to the acceptable excuses. Yes a mistake may happen but there is an acceptable limit to mistakes," Nuri al-Maliki said of the deaths of 24 Iraqis in the western town last November.
"We are worried about the increase in 'mistakes'. I am not saying that they are intentional. But it is worrying for us," he said in an interview in his offices in Baghdad.
Meanwhile, this afternoon a joint Iraqi-US security body said US forces had killed "by mistake" two women who were en route to a maternity hospital north of Baghdad.
An incident report by the joint body of the Iraqi army and US forces in Salahaddin province said the two women were shot and killed in the small town of al-Mutasim yesterday.
A brief statement from the Joint Coordination Centre named them as Saleha Mohammed, 55, and Nabiha Nasif, 35.
"US forces killed two women by mistake ... when they were heading to a maternity hospital in a taxi," it said, without specifying if either of the women was pregnant.
A police source said the driver of the car was wounded.
The US military said a car had entered a "clearly marked prohibited area" near an observation post.
Elsewhere, a sports anchorman for Iraqi state television was gunned down in Baghdad today, police sources said.
Gunmen killed the Iraqiya station's Ali Jaafar as he left his home, the sources said.
Several journalists from the government-funded station have been targeted by insurgents waging a violent campaign to topple US-backed Iraqi leaders.
The slaying came two days after a roadside bomb killed two members of a CBS television crew, cameraman Paul Douglas and soundman James Brolan, and seriously wounded correspondent Kimberly Dozier.
More than 70 journalists have been killed in Iraq since the US invasion in 2003.
Most have been Iraqis.
Agencies