The presidential run-off in Guinea, due to take place on 18 July, has been postponed, the country's electoral commission has said. Officials say more time is needed for the Supreme Court to investigate allegations of fraud. Nobody won a clear majority in the landmark 27 June first round. Guinea has been governed by a military junta for the past 18 months since the death of its long-time leader, Gen Lansana Conte. The second round pits former Prime Minister Cellou Dalein Diallo, who gained 40% of the vote, against veteran opposition leader Alpha Conde, with 21%. The election was the first democratic vote in the mineral-rich West African state since it gained independence from France in 1958. No new date has been set for the second round, when a candidate needs more than 50% to be declared the winner. Resignation threat The country descended into chaos last September after troops killed more than 150 pro-democracy demonstrators. A few months later the junta leader was shot and injured by an aide implicated in the massacre. Regional mediators intervened in the crisis and the new junta leader, General Sekouba Konate, promised to hand over to civilian rule. Earlier this week, Gen Konate threatened to resign, saying he had been insulted by opposition politicians, who have criticised last month's poll. Mali's president has led diplomatic efforts to persuade him to stay on as interim leader until the transition to civilian rule is complete. Guinea is the world's largest exporter of the aluminium ore bauxite. It also has important deposits of iron ore. Despite its mineral wealth, the country is one of the poorest in West Africa. Credit: BBC