President Joseph Kabila has won the Democratic Republic of Congo's election, provisional results show. He obtained 49% of the vote against 32% for veteran opposition leader Etienne Tshisekedi, the election commission chief said. The announcement has been delayed since Tuesday, with election officials blaming logistical problems. The opposition has complained of fraud and security is tight in the capital, Kinshasa, amid fears of violence. DR Congo is rich in minerals such as gold, diamond and coltan, which is used in mobile phones. But years of conflict and mismanagement mean it recently came bottom of a survey of living standards around the world. Riot police are patrolling the streets of the capital, seen as an opposition stronghold in this country which is still recovering from years of conflict in which some four million people died. The BBC's Noel Mwakugu says the mood in opposition districts of Kinshasa is quiet and sombre. Many shops and stalls in the city's markets have been closed for most of the week. "The Independent National Electoral Commission certifies that candidate Kabila Kabange Joseph has obtained the simple majority of votes," said election commission chief Daniel Ngoy Mulunda. On Thursday, he said the results had been delayed again in order to "assure the credibility" of the numbers. In the eastern city of Goma, people started to celebrate as soon as the results were announced on national TV and radio, reports the BBC's Joshua Mmali in the city. Mr Kabila enjoys greater popularity in eastern areas, where his origins lie and where he is credited with helping to end the war. However, he is less popular in the west, partly because he is not fluent in the local Lingala language and because some see him as representing foreign interests. The results still have to be ratified by the supreme court. International protests Mr Kabila, 40, has been president since 2001, following the death of his father, Laurent. In 2006 he won the first elections since the end of a five-year conflict and is now due to be sworn in on 20 December for his second term. Earlier this year, the constitution was amended so that the candidate with the most votes wins the elections, removing the need for a second round. As well as the presidential race, more than 18,000 candidates contested 500 parliamentary seats. Mr Tshisekedi, 78, campaigned for multi-party democracy during the years of former leader Mobutu Sese Seko but this was the first time he has contested an election. His supporters have been protesting in South Africa, Belgium, France and the UK, accusing the international community of backing Mr Kabila Four other candidates have said the election should be annulled because of alleged fraud, including pre-marked ballot papers. Voting material did not arrive in some polling stations for four days after the election was supposed to have been held. Election officials used helicopters from the UN peacekeeping mission to deliver material to remote parts of the country, which is two-thirds the size of Western Europe but with hardly any paved roads or railways. But the African Union and four other African observer missions said the polls had been "successful" and urged both sides to show restraint. The European Union observer mission said its preliminary findings showed that the polls were marred by "numerous irregularities, sometimes serious". Several thousand people last weekend fled Kinshasa for neighbouring Congo-Brazzaville as fears grew that violence would escalate once completed results are published.