The United States on Saturday said that 1,200 police and judicial officials would go to Iraq to help restore order.
The US-led coalition, trying to restore calm in cities wracked by violence and looting since the regime lost power, called on Baghdad's police to return to work.
At the US Central Command in Qatar, Brigadier General Vincent Brooks said, "Consistent with work we do in other parts of the world, Afghanistan for example, a rewards programme has been established for information leading to the capture of key [Iraqi] leaders."
A BBC correspondent reported that Shias were having gun battles with Sunnis throughout Baghdad.
In Kirkuk, Kurdish fighters began withdrawing and US forces started establishing control.
In the northern city of Mosul, 15 to 20 people were killed and over 200 wounded in fighting between Arabs and Kurds, hospital sources said.
US marines claimed that they had discovered an enormous cache of suicide bomb vests in a school in central Baghdad.
The black leather vests with wires running along them weighed about 8kg and were filled with long rectangular blocks of C4 plastic explosive and hundreds of ball bearings.
PTI