Five opposition candidates in Burundi's upcoming presidential election have announced they are boycotting the vote because they believe it will be rigged.
Among those who officially withdrew their candidacy Tuesday is Agathon Rwasa, leader of the rebel group-turned political party Forces for National Liberation and a main rival to President Pierre Nkurunziza.
Rwasa and the four other candidates are accusing the electoral commission of failing to prevent fraud in last week's local elections, in which the ruling party won with 64 percent of the vote.
The opposition rejected the result, but European observers said the elections met international standards.
The June 28 presidential poll is expected to go ahead despite the boycott, with President Nkurunziza widely expected to win a second term. The only remaining challenger is his deputy, Yves Sahinguvu.
The elections this year are aimed at capping a five-year transition to democracy, started by peace agreements that ended Burundi's civil war in 2005.
Some information for this report was provided by AP, AFP and Reuters.