Seventeen people, including 13 Iraqis and four Westerners, have been killed in a suicide bomb attack in central Baghdad, police say.
Western contractors are always at risk of attack
More than 33 were injured in the explosion targeting an armoured convoy used by Western contractors in Tahrir Square - a busy shopping area.
Police said they believed four bodies taken from a charred vehicle were those of American security contractors.
The attack came hours before a reported deal to complete the new Iraqi cabinet.
Insurgents have killed at least 250 people since the formation of Prime Minister Ibrahim Jaafari's cabinet last month.
Mr Jaafari has been struggling to bring Sunnis into his government and take the sting out of the insurgency.
According to unnamed sources, the latest agreement would see Saadoun al-Dulaimi, a Sunni Arab, as defence minister with Ibrahim Bahr al-Uloum, a Shia, filling the oil ministry portfolio.
Saturday's attack at 1105 (0705GMT) sent a large plume of black smoke into the sky as ambulances converged on the scene, one of the capital's busiest intersections.
Television footage showed the remains of several bodies lying in Tahrir Square.
Some of the wounded were girls from a nearby school.
Foreign officials and security contractors move around Baghdad in convoys of four-wheel-drive vehicles accompanied by armed guards.
They have often been targeted by insurgents.
But Iraqi police and army recruits have also been coming under more attacks, says the BBC's Jim Muir in Baghdad.
Iraqi civilians have also been deliberately targeted and the Americans have also lost at least 15 soldiers killed in the latest wave of violence, our correspondent says.
On Friday, at least 16 people were killed in a car bomb attack in a market south of Baghdad.
At least 23 people were killed in suicide bombings and gun attacks on police and army targets in Baghdad on Thursday.
On Wednesday, at least 50 were killed in an attack on police recruits in Irbil.