The fiercest attack was in the central Iraqi city of Karbala, where three US soldiers and two Iraqi policemen were killed in an overnight ambush.
Another US soldier was killed and two more wounded in an explosion on Friday morning in capital Baghdad.
A US army spokesman said its troops had been ambushed in Karbala.
"At approximately 11.30 pm (20:30 GMT) yesterday a routine Iraqi patrol accompanied by American military police was attacked by Iraqis from the roof of buildings in the vicinity of the al-Abbas mosque," the spokesman added.
The US-led occupation army blamed bodyguards of a local Shia cleric for the attack.
"The attackers, who are bodyguards of religious leader Mahmud al-Hassani, used rocket-propelled grenades and AK-47 rifles. They were about 20 to 30 attackers," the US army spokesman said.
"It was an unprovoked attack. It was an ambush," the spokesman added.
Anti-US feelings are running high
The latest deaths took to 101 the number of US troops to have died in action in Iraq since President George Bush declared major combat over on 1 May.
Earlier on Thursday, US occupation soldiers backed by tanks moved into a stronghold of Shia cleric Muqtada al-Sadr in Baghdad.
Iraqi police also arrested at least 12 of the anti-occupation cleric’s followers after evicting them from a municipal building in Baghdad’s densely packed al-Sadr suburb.
The cleric’s followers had seized the building last week. At least six US tanks blocked access to the building that was surrounded by armoured military vehicles.
Occupation forces are scrutinising al-Sadr’s activities but officials did not elaborate what the actions were.
Al-Sadr heads a thousands-strong armed militia called the al-Mahdi army. His groups had been using the municipal building to run its own social services.
Iraqi police said they would release the detainees if clerics speaking for al-Sadr came to the police headquarters and acknowledged that they had been acting improperly at the municipality building.
Police officials also pointed out that there was no place in Iraq for independent militia groups, such as al-Sadr’s.
Meanwhile, US troops shot dead a Jordanian taxi driver and three of his passengers in Baghdad.
Occupation forces opened fire at the car after it failed to stop at a checkpoint, according to the Amman taxi firm.
Employers at the taxi firm said the driver “probably did not see the American checkpoint in the dark” and did not stop.
The walk to school for many Iraqis
US military officials denied the report, saying the cars' occupants were killed when their vehicle crashed into a tank at a checkpoint.
And in Tikrit, a four-year-old Iraqi girl was killed and her sister wounded when a roadside bomb was detonated as they walked to school.
A US army medic said Jihan Omran died after she was taken to hospital.
Resistance to Turkish troops
On the diplomatic front, Iraqi Kurdish leader Masud Barzani was quoted as saying that there would be “dire consequences” if Turkish troops entered Iraq and threatened to resign from the Governing Council.
Ankara has offered to send forces to Iraq but the US-appointed Council opposes involvement of troops from any of Baghdad’s neighbours.
“It is not just the Kurds who are opposed to Turkish military presence,” Barzani was quoted in the Ashark al-Awsat newspaper as saying.
Kurds, who dominate northern Iraq, are particularly opposed to Ankara’s presence. They accuse Turkey of trying to stir up ethnic tensions between them and the Turkmen minority in Iraq.
Barzani heads the Kurdish Democratic Party. The Turkish military has warned that its troops would respond to any Iraqi Kurd attack. Earlier this week, a blast was detonated outside of Turkey’s embassy in Baghdad, leaving several people hurt.
“Our position is very clear and firm. The Turks will bear the responsibility for sending their troops into Iraqi territory despite Iraqi opposition,” said Barzani.