The two US soldiers were killed in a roadside bomb attack on their convoy in the Baghdad area, capping one of the deadliest months for the US military since the start of the war in March 2003.
The latest fatalities brought to 125 the number of US soldiers killed since 1 November. Four UK soldiers were also killed in the period.
Nearly a week into Operation Plymouth Rock, launched by US
marines, British troops and Iraqi forces in the area south of Baghdad, two marines and three anti-US fighters were killed on Sunday.
Thirteen US marines and two civilians were also wounded when mortar shells struck a military base south of Baghdad, a marine spokesman said.
In a related incident, four Iraqi national guardsmen were killed in an attack in the town of Baghdadi in al-Anbar province.
"A car bomb exploded near a national guard checkpoint, killing four members of this force and wounding three more," a police source said on Monday.
The attack occurred in the same town in the province of al-Anbar where 10 policemen were killed in a car bomb attack a month ago.
Captain David Nevers from the 24th Marine Expeditionary Unit said at least three anti-US fighters were killed in separate incidents, as US-led forces continued their sweep of the area, which had become a no-go zone in recent months and made any trip south of Baghdad extremely perilous.
US-led forces want to subdue
opposition before the elections
Thirty-two suspected Iraqi fighters were detained on Sunday, bringing to more than 180 the number of people held since the start of the operation.
The operation to control the area followed from the massive assault launched on 8 November on the western city of Falluja.
US-led forces moved on Falluja in the largest military operation since the 2003 invasion, in a bid to remove what was seen by the US military and Iraq's interim government as one of the main obstacles to holding viable polls in January.
In continuing operations in the western Iraqi province of al-Anbar, which includes Falluja and the town of Ramadi, three US servicemen were killed on Sunday, reported an AFP journalist embedded with US troops.
He also said two others were killed on Friday in the same
The US military could not immediately release details of the circumstances of the deaths.
"The level of criminal operations has receded and is continuing
to drop following the operation in Falluja"
Iraqi interim prime minister
Nevertheless, interim Prime Minister Iyad Allawi insisted on Monday that the general level of violence had dropped since Falluja had been taken.
"The level of criminal operations has receded and is continuing to drop following the operation in Falluja," he said on the state-owned Iraqiya television, in response to questions from viewers.
On Friday, several major Iraqi parties had argued that security conditions did not allow the organisation of viable polls across the country and called for a six-month delay.
But most of the relevant authorities rejected the idea and said everything would be done to hold the elections on 30 January, as scheduled.
"Postponing the elections is out of the question," electoral
commission chairman Abd al-Husayn al-Hindawi said on Saturday after examining a request by 17 organisations, including 10 major parties.
Iraqi oil pipelines are a frequent
target for attacks
Opponents of a delay argue that the current US-appointed administration's lack of legitimacy is one of the factors fuelling support for anti-US attacks.
They add that there is no guarantee security conditions will be better in six months.
Meanwhile, the country's main economic lifeline came under threat again when a pipeline between two major refineries was attacked.
A source at the Baiji refinery - which provides power for large swathes of northern and central Iraq - said the flow of oil in the damaged pipeline had been slashed by 80%.
On Sunday, a pipeline between the Rumaila oilfields and the
Basra terminal - which accounts for the bulk of Iraq's exports - was also damaged but production was not affected, said the South Oil Company.