Ivory Coast's electoral commission has said opposition candidate Alassane Ouattara has won the presidential run-off but the Constitutional Court has contested the announcement. The BBC's John James in the main city Abidjan says there will now be a tug of war between the two bodies with the outcome unclear. Supporters of President Laurent Gbagbo had tried to block the result, saying there had been fraud in the north. Former rebels control this area. It is also where Mr Ouattara is most popular. The election is intended to reunify the world's largest cocoa producer. The announcement of the result of Sunday's run-off has been much delayed, leading to heightened tension in the country. At least four people were killed on Wednesday night in an attack on an office of Mr Ouattara's party. The Constitutional Court said the electoral commission's failure to announce the result by Wednesday's deadline meant it was taking over the declaration. But at about the same time, electoral commission head Youssouf Bakayoko said Mr Ouattara had won 54% of the vote. He was speaking under armed guard at a hotel, rather than from the commission headquarters. Source: BBC