The president is being sworn in for a second five-year term
Malawi's President Bingu wa Mutharika has been sworn in for a second five-year term.
During an inauguration ceremony attended by several regional leaders, Mr Mutharika said fighting corruption would continue to be a top priority.
Earlier Malawi's election commission said he had won more than 2.7m votes, with nearest rival John Tembo taking nearly 1.3m.
The opposition, which contests the results, boycotted the inauguration.
During the ceremony in the main stadium in Blantyre, Mr Mutharika said: "I shall continue to fight corruption because it is evil... it robs the poor and denies them their legitimate right to a decent living."
Presidents attending the event included Zimbabwe's President Robert Mugabe, Zambia's Rupiya Banda, and Mozambique's Armando Guebuza.
The BBC's Raphael Tenthani at the event says the 50,000-capacity arena was packed full, with the official blue party colour of Mr Mutharika's Democratic Progressive Party (DPP) everywhere.
DPP supporters sang "Moses Wa Lero", describing Mr Mutharika as a "modern-day Moses".
Mr Mutharika, a 75-year-old former World Bank official, saw his DPP take the lion's share of parliamentary votes.
Mr Mutharika's running mate Joyce Banda, becomes the first female vice-president in Malawi's history.
Election commission head Anastacia Msosa announces the result
International poll monitors said they were "extremely concerned" by what they called a lack of balanced coverage from state media during the campaign.
Mr Tembo rejected the official results, telling reporters that they had been "rigged".
But his opposition coalition partner, former President Bakili Muluzi, who had backed Mr Tembo after being himself barred from seeking a third term, congratulated Mr Mutharika.
The poll followed a five-year feud between Mr Muluzi and his successor.
Mr Mutharika was elected in 2004 but then fell out with Mr Muluzi, accusing his one-time backer of trying to stonewall his anti-corruption drive.
Poverty, agriculture and health care are the big issues for Malawi, where two-thirds of the 14 million population lives on less than $1 a day and Aids has orphaned an estimated one million children.
The general feeling here in Malawi is that of jubilation. Many of us knew that Bingu would win but certainly not with a landslide victory. This was a protest vote. Not many Malawians would have wanted to go back to UDF or MCP rule. On the face of it and to every Malawian, it's clear that the country is on course to make considerable strides in development.
Chivwiko, Blantyre, Malawi
It is inevitable that John Tembo will attempt to muddy the water by disputing the election results, but the BBC should be clear that this is a very different situation to the recent polls in Kenya and Zimbabwe. Mutharika has enormous popular support, and has had the most successful economic, social and governance record of any Malawian president. We hope that his is able to use the new DPP legislative majority for the benefit of the Malawian people.
Nick, Lilongwe, Malawi
Malawi has once again renewed her reputation of being the Warm Heart of Africa, a shining beacon of African Democracy. When the World was in anticipation to witness electoral upheavals, now so much akin to the continent, Malawians have instead demonstrated that peace and tranquility can lace up elections in Africa when they turned out in large numbers to vote into Government a man who by any measure deserves to lead them for another 5-year term.
Paul, Lilongwe, Malawi
The fact is that Dr Bingu Wa Mutharika is a genuine winner of the elections. For the first time in the history of elections in Malawi, people have not voted on regional, tribal and religious lines. This is what has deceived Tembo into thinking that Bingu has rigged the elections.
African leaders should come to terms with the bitter fact that in every presidential election there can only be one winner. I can describe this year's elections as the most successful in the history of Malawi. The whole electoral process was very transparent. No single incident of violence was reported on the voting day. Malawi's democracy is fast maturing.
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