Guinea-Bissau's president-elect Joao Bernardo "Nino" Vieira, center, and his wife Isabel Romano Vieira, right, greet supporters

Final results from last month's presidential runoff election in Guinea-Bissau give the victory to former military ruler Joao Bernardo Vieira.

Electoral officials say Mr. Vieira, also known as "Nino," received 52 percent of the vote, compared with 48 percent for his rival, interim leader Malam Bacai Sanha.

Mr. Sanha has said he will not accept the results, alleging voter fraud.

Both candidates in the July 24 runoff election had pledged to end years of political instability.

Guinea-Bissau has been plagued by numerous coups and coup attempts since gaining independence from Portugal in 1974.

Mr. Viera took power in a 1980 coup and ruled 19 years until he was ousted during a civil war.