Seven US troops have been killed in Iraq, including four in the western province of Anbar, where gains in security were hailed this week by US President George W. Bush during an unannounced visit to the region.
The US military said today that four Marines were killed in the vast desert province yesterday while conducting combat operations. It gave no further details on one of the deadliest days for troops in Anbar in months.
The military also said three soldiers were killed in the northern province of Nineveh yesterday when an explosion hit their vehicle.
The deaths take to more than 3,750 the number of US soldiers killed since the start of the US-led invasion in 2003. Eighteen soldiers have died so far this month.
Mr Bush visited Anbar on Monday and said improved security there was an example of what could happen elsewhere in Iraq.
From 2003 until last year, Anbar was the heartland of the Sunni Arab insurgency and the most dangerous part of Iraq. But a rebellion by Sunni Arab tribal leaders against Sunni Islamist al-Qaeda, which once controlled large swathes of the region, has sharply reduced levels of violence.
The US commander in Iraq, General David Petraeus, will likely highlight the success in pacifying Anbar when he presents a long-awaited report to Congress early next week on Mr Bush's decision to send 30,000 extra troops to Baghdad and Anbar.
The testimony by Petraeus and US Ambassador Ryan Crocker will be vital to any decision Mr Bush takes on troop levels in the face of demands from opposition Democrats and some senior Republicans for US forces to start leaving Iraq.