Four people have been shot dead in Ivory Coast's main city of Abidjan after a march to protest at the killing of seven female demonstrators last week.
The shooting has been blamed on rogue army officers supporting disputed President Laurent Gbagbo.
Mr Gbagbo refuses to cede power although rival Alassane Ouattara is internationally recognised as the winner of last year's poll.
The United Nations says 450,000 people are believed to have fled from their homes as a result of the post-election crisis.
Meanwhile, the United States State Department says a move by Mr Gbagbo to take the cocoa sector into state hands amounts to theft.
Ivory Coast is the world's largest supplier of cocoa beans.