UN Secretary-General Ban Ki-Moon has called on Ivory Coast President Laurent Gbagbo to step down as he was confined to the Presidential Palace after a day of heavy fighting. Forces supporting Alassane Ouattara, the UN-recognised President of the west African nation, have swept across hundreds of kilometres in recent days, capturing town after town along the way. Ban urged Mr Gbagbo, who has not been seen publicly for weeks, to step down to avoid further violence. He had refused to quit after he was declared defeated in the election in the UN-certified results. More than one million people have already fled their homes, with many of them crossing into Liberia and Ghana.