Four Iraqi fighters were also killed in Wednesday’s clashes, said police and medics.
Two US soldiers were also wounded in the twin clashes in Mosul city centre, said police.
In the first incident, Iraqis used hand grenades against a US Humvee. Occupation forces in return killed one fighter, said police captain Fathi Salah Zubaidi who witnessed the attack.
A boy in a BMW behind the Humvee that was attacked was killed and four others were wounded, said another police captain, Bassam Saleh Abd Allah.
The child's body was taken to a US military hospital. Occupation officials had no immediate comment on the clashes.
In the second incident, fighters clashed with US troops in the Ghalat neighbourhood near the Tigris.
Also in Mosul, a US soldier died from what occupation officials said was a non-combat-related gunshot wound.
Meanwhile, a rocket or mortar round struck the Italian embassy in Baghdad causing structural damage but no
injuries, reported Italian news agency ANSA late on Wednesday.
Witnesses said the missile hit the second floor of the
Italian forces and representatives have been on high alert
in Iraq since an attack killed 19 Italians in the southern city of Nassiriya earlier this month.
Marines called in
Amid an increasingly bloody guerrilla war, US defence officials announced plans to send thousands more Marines to the war-torn country in early 2004, bolstering the next wave of US troops being deployed.
US Defence Secretary Donald Rumsfeld directed the Marine Corps to send three additional battalions, along with assorted support units, to Iraq as part of the troop rotation plan for early 2004, said officials.
Defence officials portrayed the decision as fine-tuning of a previously announced troop rotation plan and not a reaction to the difficult security situation.
Instead of scaling-down troops,
the US plans to increase numbers
The exact number of Marines involved has not yet been determined.
Officials said the Marines in the three battalions would amount to at least 2700.
The support units attached to the battalions will push the total number of Marines involved even higher.
Earlier this month, Pentagon planners said Washington envisioned 105,000 troops in Iraq next May, scaled-down from the current 130,000.
The thousands of additional Marines will add to the 105,000 figure, said officials.
"This is not 'the sky is falling'...This is a minor tweak in the plan"
Anonymous US defence official
“This is not 'the sky is falling,'" said one defence official, speaking on condition of anonymity. “This is more planning. This is a minor tweak in the plan.”
The rotation plans call for a shrinking US force in Iraq in the first half of 2004, but officials also said the number of troops actually deployed will depend on the security situation.
President George Bush and Rumsfeld both have not ruled out an increase in US troops in Iraq if American commanders believe additional forces were needed.
Rumsfeld's decision also increases the role of the Marines. They played a crucial role during the invasion launched in March and later occupied south-central Iraq before leaving in September.