In another attack, a roadside bomb in the capital killed one policeman and wounded two others, officials said.

In the southern city of Najaf, Shi'ite Adil Abdul-Mahdi, one of Iraq's two vice presidents, said that about 100,000 families have been forced to flee their homes nationwide because of continuing violence. He said 90% of them were from the majority Shi'ite population and the rest from the country's Sunni minority.

Other estimates of the number of displaced families have been lower.

For example, on Friday, Dr Salah Abdul-Razzaq, spokesman of the Shi'ite Endowment, a governmental body which runs Shi'ite religious institutions, put the number of displaced people at about 90,000.