Kenya's National Commission on Human Rights says both government and opposition leaders planned acts of violence following the country's disputed presidential election.
Vice Chairperson Florence Jaoko says the commission's investigation showed the violence was not spontaneous. The commission says it has collected nearly 1,000 statements recounting more than 4,500 episodes of violence.
Earlier this month, US-based Human Rights Watch accused Kenyan politicians, local leaders, and businessmen of organizing attacks on rival ethnic groups. It also accused Kenyan police of using excessive force in putting down protests - a charge the police rejected.
More than 1,000 people were killed in riots and ethnic violence following the December 27 election.
The opposition accused President Mwai Kibaki of rigging the vote to stay in power.
Former U.N. Secretary-General Kofi Annan helped broker a peace deal that included a power-sharing agreement between Mr. Kibaki and opposition leader Raila Odinga.