Sierra Leone's National Electoral Commission says opposition leader Ernest Koroma has won the nation's September 8 presidential runoff.  Kari Barber has more from VOA's West Africa bureau in Dakar.

Opposition supporters poured into the streets to celebrate the electoral commission's naming of All People's Congress candidate Ernest Koroma winner of the nation's presidential election.

Final results show Koroma with about 55 percent of the vote and his opponent, Vice President Solomon Berewa, with about 45 percent.

The declaration of Koroma as president-elect follows a move by Berewa's Sierra Leone People's Party to prevent the release of the results because of concerns about some of the electoral commission's procedures.  A judge has postponed the hearing.

All People's Congress student leader Bai Mahmoud Bangura says as president Koroma will fight corruption while trying to  mend divisions in the country caused by the election.

"Whoever misperformed in the last regime is going to be weeded out," Bangura said. "And whoever performed to the expectations of the people is going to be incorporated."

Civil-society activist Christian Lawrence has been coordinating election monitoring teams.  He says the city is tense with the announcement.

"The political landscape at the moment is very tense.   Security is really tight in the capital city and even in the provinces," Lawrence said.

The first round of voting, held August 11th, was essentially peaceful, but in the run up to the second round supporters of the two political parties faced off in violent clashes in several cities including the capital.  This sparked fear in the nation, still recovering from an 11-year civil war that ended in 2002.

Lawrence says he hopes the new government will incorporate the losing party to create a more peaceful country.  But he says he is not optimistic this will happen.

"This is winner take all, as they normally call it, one person wins and must take all for his party," Lawrence said. "That is the fear.  It would be fine for them to work with each other.  They normally say it diplomatically, but the reality is sometimes different."

Koroma, a former life insurance executive, has said that if sworn into office he will fight corruption and revitalize agriculture and the tourism and mining industries.

Koroma has led Berewa in the vote count since results began coming out in the first round, but the two were forced into a second round after neither got the 55 percent needed to win outright.  For the runoff, third-place candidate Charles Margai threw his support behind Koroma - a critical boost.

The results can be challenged by petition to the Supreme Court within the next seven days by Sierra Leone law.

Observers cited some cases of fraud in the runoff election, such as ballot stuffing, but said it was generally free and fair.

This was the first presidential election held in the country since U.N. troops withdrew in 2005.