BAGHDAD & NAJAF - Three US marines were killed Saturday in the al-Anbar province in western Iraq, the US military said Sunday in a statement.
"Three Marines assigned to I Marine Expeditionary Force were killed in action May 29, in the Al Anbar Province while conducting security and stability operations," the statement said.
The US military also reported in another statement that a soldier had been killed and nine wounded in a mortar attack on May 25 on a military base south of Baghdad.
The statement did not specify whether the soldier was killed on Tuesday or died later of his injuries.
Another US soldier based in near the northern Iraqi city of Mosul, 370 kilometres (230 miles) north of Baghdad, has died in a non-hostile incident, the US military also said.
The soldier died on Thursday, a statement said without elaborating.
More than 800 US soldiers have now died since the start of the US-led invasion of Iraq in March of last year, according to a tally based on Pentagon figures. Of those, 590 have been killed in action.
Meanwhile militia loyal to radical Shiite cleric Moqtada Sadr attacked a US patrol on Sunday in the Iraqi holy city of Najaf breaking a fragile truce reached Wednesday, an official in Sadr's office said.
"A US patrol violated the truce by approaching Najaf from the Valley of Peace area at about 8:30 am (0430 GMT) this morning," said Sheikh Mushtaq al-Khufaji.
"Members of the Mehdi Army confronted it with rocket-propelled grenades and gunfire forcing it to retreat."
The clashes started at around 9:00 am (0500 GMT) and lasted about one hour centering around the northern extremities of the city's vast cemetery, known as the Valley of Peace, scene of fierce clashes in recent weeks between US troops and Sadr's Mehdi Army militia.
The area is less than two kilometers (one mile) from the city centre.
Many shopkeepers abruptly closed and residents rushed for shelter as Najaf's streets looked deserted again after normal life had slowly started to return to the city over the past few days following the announcement of the truce.
US tanks and armoured vehicles were also seen around the nearby 1920 Revolution Square, witnesses said.
"I saw US tanks and armoured vehicles moving from the police headquarters towards the square," said Mahdi Abdul Razak.
US troops have been stationed at the police building off the square for the past few weeks, after it was attacked by militiamen.
Khufaji said the Mehdi Army "is committed to the truce" offered by Sadr Wednesday and cautiously welcomed by the US-led coalition, but "that it is ready to respond to any US violations".
"We consider the running of US patrols anywhere outside the stretch connecting the base and the governor's office a violation of the truce," he said.
US troops have been stationed at a coalition base on the eastern fringes of Najaf for more than a month and have also deployed at the provincial governor's office since recapturing it from Sadr's militia.
US military commanders have said that they will abide by the truce but that troops will continue to run patrols in Najaf and will retain the right of self-defense if attacked.
The truce is intended to allow for negotiations on the fate of the Mehdi Army and legal proceedings against Sadr in connection with the murder of a rival cleric last year.
But it was already broken on Friday and Saturday when clashes broke out between the militia and US soldiers in nearby Kufa, killing four Iraqis and wounding 22.