The United Nations will investigate the deaths during last week's opposition demonstrations in Ivory Coast, it says.
France will conduct joint patrols with the army to restore calm
Spokesman Jose Diaz has told the BBC that commission is expected to begin the investigations soon.
Opposition leaders say more than 300 people were killed during the demonstrations that were dispersed by government forces.
But police in the commercial city Abidjan say only 37 people died.
The clashes put further strain on the peace deal between northern-based rebels and the government in the south.
Human rights organisation Amnesty International has said it was disturbed by the excessive use of force against unarmed demonstrators.
"We have received a formal request from the committee monitoring the peace agreement in Ivory Coast and we have began setting up the mission to investigate the alleged human rights abuses," said Mr Diaz from the UN High Commission for Human Rights.
He said the allegation include summary and extra-judicial executions, rape and sexual violence, arbitrary arrests and detention among
other reported abuses.
Ivorian Security Minister Martin Bleou said the killings may have been the work of "parallel forces" disguising themselves in official uniforms.
"Several credible witness statements reveal that individuals in combat fatigues armed with automatic pistols, and others with Kalashnikovs, are moving around at night sowing terror in certain districts," he said.
France, which has some 4,000 troops in Ivory Coast, has agreed to conduct joint patrols with the army in an effort to restore calm after the deadly clashes.