Kenya's main opposition party has called for new demonstrations to protest the disputed re-election of President Mwai Kibaki.

The Orange Democratic Movement announced plans Friday to hold rallies in more than 20 locations next Wednesday, Thursday, and Friday. In a statement, the party specifically asked police to provide security for a mass rally Wednesday at Nairobi's Uhuru Park.

Kenyan police quickly responded, saying they will not allow the opposition to hold the rallies.

Authorities have banned all protests since Kenya erupted in violence nearly two weeks ago, after President Kibaki was declared the winner of the December 27 election.

ODM supporters who tried to gather in Nairobi last week were stopped by police using tear gas and water cannon.

Foreign mediators trying to end the crisis have failed to secure an agreement or a meeting between Mr. Kibaki and opposition leader Raila Odinga.

African Union chairman John Kufuor and the top U.S. diplomat for Africa, Jendayi Frazer, both left Nairobi Thursday after their mediation efforts fizzled. Former U.N. Secretary-General Kofi Annan has agreed to take over the negotiations next week.

The opposition maintains that President Kibaki stole the election and has called for him to step down. Violence triggered by the dispute has killed more than 500 people.

The United States announced Thursday it is donating $5 million to help Kenyans made homeless by the violence.

Some information for this report was provided by AFP, AP and Reuters.