A policeman and civilian were killed in overnight clashes hours before the start of Burundi's presidential elections, already hit by opposition boycotts and protests over President Pierre Nkurunziza's decision to run for a third term. Blasts and gunfire echoed around the capital before polling stations opened on Tuesday in a nation grappling with its worst crisis since a civil war ended in 2005. It has faced weeks of demonstrations, a failed coup and clashes between rebel soldiers and the army. Opponents accuse Nkurunziza of violating the constitution by seeking another five years in office. Western donors and African states, worried about stoking tensions in a region with a history of ethnic conflict, urged Burundi to postpone the poll. Nkurunziza cites a court ruling saying he can run again. The government said they had already delayed the vote as long as they could and promised a fair poll. Voting began in rural areas and dozens queued to cast ballots in areas of Bujumbura that are strongholds of Nkurunziza supporters. But in some other districts of the capital there were only trickles of voters in the morning while some polling stations were closed even after the official 6 a.m. start. A Reuters witness saw one dead civilian man with no obvious injuries on the ground in the Niyakabiga district of the city surrounded by crowds. Presidential adviser Willy Nyamitwe blamed opponents and those behind protests for overnight violence, saying a policeman and civilian were killed. "People do it to intimidate voters. They don't want the voters to go to the polls," he told Reuters. One 40-year-old voter in Bujumbura, Ferdinand, said he would vote for Nkurunziza, a soccer fan who is often pictured rolling up his sleeves to work with people in the fields, because he had "a good programme of development for ordinary citizens." "We need change. We need new blood," said Wilson, a mechanic in Bujumbura who did not give his full name. He added that he would not vote because Nkurunziza's rivals were not running. Opponents say the president's re-election bid is undermining a peace deal that ended a civil war that pitted rebel groups of the ethnic Hutu majority, including one led by Nkurunziza, against the army, led at the time by the Tutsi minority. The tension worries neighbouring Rwanda, which has the same ethnic mix and suffered a genocide in 1994 that killed 800,000, mostly Tutsis as well as moderate Hutus. "The outcome of these elections will be void," Jean Minani, one of the opposition presidential candidates, said on the eve of the vote, speaking with other candidates participating in the boycott. The United States and European nations, major donors to the aid-reliant country, have halted some aid. The African Union said it would not send observers as the vote would not be fair. "An election with neither observers nor opposition taking part cannot be democratic at all," said Jean, 50, a resident of Bujumbura's Nyakabiga district that had been a hotbed of protests which have subsided in the last few weeks. Burundi's electoral commission said opposition names were still on the ballot paper and any votes for them would be counted. It also counted votes for opponents who boycotted a June parliamentary poll that Nkurunziza's party won easily.