A third day of heavy fighting has been reported in the Ivory Coast city of Abidjan.
Hundreds of people are reported to have been massacred in the western town of Duekoue, as rival forces continue to battle for control following a disputed presidential election.
Internationally recognized President Alassane Ouattara's fighters are trying to oust troops loyal to the incumbent, Laurent Gbagbo, who has refused to surrender power since losing last November's election.
In Duekoue, between 800 and 1,000 people are reported to have been killed.
Aid agencies and the United Nations say there are indications that many hundreds of the killings appear to have been carried out by Ouattara's forces.
The group Human Rights Watch says it has documented abuses by supporters of both sides that could amount to war crimes.
In a statement, U.S. Secretary of State Hillary Clinton called on Gbagbo to step down "immediately."
compiled from agency reports