The death brings US fatalities in the country to 148 since the start of the war in April, more than during the whole of the first Gulf War, which began in 1991.
The latest incident came as Deputy Defence Secretary Paul Wolfowitz arrived on an unannounced visit to boost US troops' flagging morale.
Before his arrival soldiers defused at least one explosive device planted on a highway leading to Baghdad's international airport as
Troops at the scene confirmed the find as they closed off the road while sappers worked to make safe the bomb.
The US military has declined comment but witnesses said at least one other device was found.
Wolfowitz is one of the architects of the US-led war on Iraq.
On Wednesday, US Central Command chief, General John Abizaid conceded that his troops in Iraq were facing guerrilla war.
Anti-US sentiment in the country has been running high with many Iraqis accusing the occupiers of failing to provide them with basic necessities and services as well as security.
Earlier today, an Iraqi imam told worshippers in a sermon during Friday prayers to resist the American occupation. He also called for the creation of an Islamic army.
Muqtada al-Sadr said the US-backed governing council was illegitimate and called for a constitution that fairly represented the Iraqi people. He delivered his speech to thousands in a mosque in Najaf, southern Iraq and home to the country’s Shi’ite majority.
His sermon is a blow to the US administration’s hope that the creation of a governing council would make Iraqi’s feel they were being increasingly included in the running of their country.
“We condemn the Governing Council headed by the United States,” al-Sadr told worshipers. “An Islamic army must be created and volunteers for this great army must come forward.”
Iraq’s Governing Council, comprising 25 representatives and supposedly reflecting the country’s ethnic and religious composition, met for the first time on Sunday.
Al-Sadr is highly respected amongst the country’s 13 million Shi’ite muslims and is the son of Ayatollah Mohammed Sadiq al-Sadr, assassinated in 1999 by suspected Iraqi intelligence officers.
Baghdad imam praises resistance
In Baghdad, a Sunni Muslim imam praised those resisting US forces, saying they were “symbols for Iraqis to be proud of.”
Hareth al-Dari also rejected the Governing Council, blaming it for dividing the Iraqi peoples and causing “hostility between the sons of this society.” He is imam of the Um al-Qura mosque on the western outskirts of the city.
The US military said yesterday its forces were on high alert in preparation for more resistance operations. Attacks may be planned to coincide with the anniversary weekend of Saddam Hussein’s Baa’thist party’s accession to power in 1968.
Further attacks on US soldiers
An Al Jazeera correspondent reported that the US headquarters in the Diyala region came under rocket-propelled grenade (RPG) attack Friday morning.
Two US soldiers were alo injured in a hand-grenade attack. Their four assailants were shot dead.
An American patrol was also fired at in Baquba but there were no reported casualties.
Currently, there are some 230,000 US troops serving in and around Iraq, including nearly 150,000 inside Iraq and 12,000 from Britain and other countries