Iraqi Prime Minister Nouri Maliki is demanding a fresh inquiry into the alleged rape and murder of an Iraqi woman by US troops.
Iraqi Prime Minister Nouri Maliki questions coalition immunity
Her father, mother and young sister also died in the March attack at their home in Mahmoudiya, south of Baghdad.
"We will demand an independent Iraqi inquiry, or a joint investigation with multinational forces," Mr Maliki said during a visit to Kuwait.
A former US soldier has been charged with rape and murder.
Up to four other soldiers are being investigated.
The inquiry is the latest in a series examining alleged abuses by US troops.
Mr Maliki also called for the immunity granted to coalition troops to be reviewed.
"We do not accept the violation of Iraqi people's honour as happened in this case. We believe that the immunity granted to international forces has emboldened them to commit such crimes," he said.
Up to four US soldiers are being investigated in the case
But a US military spokesman, Major-General William Caldwell, said American soldiers were not immune from prosecution because they were accountable under military law.
Gen Caldwell also revealed that the US army was investigating the leadership of the unit to which the soldiers belonged, particularly the question of why they were operating unsupervised.
The man charged in the case, Steven Green, 21, appeared in court in North Carolina on Monday accused of rape and murder.
Sunni Justice Minister Hashim al-Shebli called the alleged attack "monstrous and inhuman" and called on the UN Security Council "to stop these violations of human rights".
Two Iraqi legislators said condemnation was not enough and called on the prime minister to be summoned to parliament to give assurances that justice would be done.
The prime minister's demands came as US and Iraqi troops raided a hospital in the Sunni insurgent stronghold of Ramadi, west of Baghdad.
More bomb attacks
They believe it was being used by insurgents to launch mortar and sniper attacks on them.
Insurgent attacks have continued unabated since Abu Musab al-Zarqawi, the leader of al-Qaeda in Iraq, was killed by a US air strike earlier this month.
A policeman surveys the bomb damage in central Baghdad
On Wednesday, a car bomb exploded near a mosque in Baghdad killing six people and injuring 17 others, Interior Ministry and police sources said.
Another two people were killed in a separate explosion near a restaurant in central Baghdad.
And a further two people were killed and four injured in a suicide car bomb attack in the northern city of Mosul.
A Baghdad official told Reuters that Baghdad's central mortuary had received 1,595 bodies last month - the highest number since the February bombing of a Shia shrine sparked a wave of sectarian killings.
The kidnappers of a Sunni MP, Taiseer Najah al-Mashhadani, have now issued demands for her release, including a timetable for the withdrawal of US troops and a guarantee of safety for Shia places of worship.
Iraqi Vice President Tareq al-Hashemi told AFP: "We do not have precise information about the kidnappers but we know they are a member of a group that belongs to the government and to the political process."
The MP and seven of her bodyguards were kidnapped on Saturday in an ambush that prompted Sunni MPs to boycott parliament.