The Higher Ministerial Committee formed to investigate civilian deaths during the initial protests revealed in its final report that 157 people perished, including eight members of the security forces.
Most of the fatalities occurred during clashes between protesters and security forces deployed to protect the headquarters of political parties and government buildings, according to commission member Ali al Bayati.
He also denounced the “excessive” use of tear gas and batons by police.
All but 56 of the 399 people arrested have already been released, the commission said, urging protesters to remain peaceful and the security forces to avoid confrontations.
The rights body advocated the organization of a national conference with the mediation of the United Nations to come up with “realistic” solutions to Iraq’s problems.
Earlier Wednesday, thousands of Iraqis headed to Baghdad’s Tahrir Square for a sixth day of protests.
Last Friday marked the return of the mass demonstrations that rocked Iraq at the start of this month amid anger over unreliable electric and water service, lack of economic opportunity and pervasive corruption.