The bomb blew up as a convoy of three civilian sports utility vehicles passed just outside an entrance nicknamed "Assassins' Gate" by US forces, one of the main entries to the heavily fortified "Green Zone," home to the US and British embassies and to Iraqi leaders.
Two South African private security guards were killed in the attack, said
US embassy spokesman Elizabeth Colton. Three others in the car, a South
African, an Iraqi and an American, were also injured in the attack, two seriously, Ms Colton said.
The Iraqi interior ministry earlier reported that three people had been
killed in the blast, first reported to be the work of a suicide car bomber.
US forces immediately cordoned off the area, while Apache attack helicopters circled overhead.
The attack comes barely one month ahead of the December 15 general
elections in Iraq, the third round of voting since the 2003 fall of the Saddam
Hussein regime.
Ramadi violence
In Ramadi, five civilians were killed and two injured in a bomb blast targeting a US convoy, hospital sources said. The dead included a woman and a child.
None of the vehicles in the US convoy were damaged, according to a witness.
Ibrahim sweep
Meanwhile more than 600 Iraqi and US soldiers searched homes in Dur, the
home village of Izzat Ibrahim al-Duri, Saddam Hussein's former number two, amid reports of his death.
The force cordoned off the village and started house searches, an Iraqi army officer in Dur said.
The US-led coalition said late Sunday there was still a 10 million dollar bounty for information leading to Ibrahim's capture or gravesite, an announcement that appeared to cast doubt on reports of the 63-year-old's death.
Saddam's outlawed former ruling Baath party issued a statement Friday saying that Ibrahim, the most senior member of the ousted regime still at large, had died of leukemia.
But a website also claiming links to the Baath party on Sunday apologized
for what it described as the false reporting of Ibrahim's death, claiming he
was still alive.
Meanwhile a force of 800 US marines along with Iraqi soldiers swept into a
village just southeast of the former rebel bastion of Fallujah searching for
suspects and weapons, an AFP correspondent reported.
The force cordoned off the village of Zaidon and detained several hundred
people for questioning, though some were released quickly.
The force encountered no resistance and plans to search the town for
weapons, the correspondent said.
Human rights report
Amid the violence, a UN rights report warned that "the proliferation of
armed militias, criminal and terrorist organisations acting with impunity
constitutes a major challenge to law and order and a threat to the security."
Iraqi authorities "need to focus on fighting widespread impunity, which if
not addressed, will further undermine the rule of law and peaceful coexistence," it added.
The UN Assistance Mission in Iraq (UNAMI) bi-monthly report suggested that Iraqi police and special forces abuse human rights during security sweeps, while insurgents' bombings of civilians risks sparking inter-communal clashes.
The report also noted concern over the large number of detainees, which
"continued to increase due to mass arrests carried out during security and
military operations."
The UN mission gave no figures, but officials last month suggested some
18,000 people were being held in US- and Iraqi-run jails.