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

Guinea-Bissau's electoral commission has confirmed that Joao Bernardo Vieira won last month's elections, with 52 percent of the vote in a second round run-off.

Guinea Bissau's election commission named former army ruler Joao Bernanrdo Vieira the country's new president on Wednesday, dismissing complaints by losing candidate Malam Bacai Sanha who filed a 135-page document asking the commission to annul the results because of alleged fraud.

Celebrations by Vieira supporters were quickly dampened by fear that it would incite clashes with the opposition from the ruling PAIGC party headed by Mr. Sanha.

Alain Mbarrow, a journalist covering the election in Bissau, says police are on the streets to quell possible violence in reaction to the commission's ruling.

"People are worried about the position taken by the candidate of PGIX, the ruling party's Malan Bacai Sanha," he said.

He said people are continuing to leave the capital, Bissau, in hopes of finding more secure places inside the country.

Though Mr. Sahna urged his supporters to remain calm, he said he is going to continue to fight to stay in office. He said he will take up the issue with the Supreme Court which must still finalize the election results.

Despite the electoral body's announcement, West Africa analyst Chris Melville, from the London-based World Markets Research Center, says a Vieira victory may bring new problems to the tiny coup-ridden nation.

He says when Mr. Vieira takes office, he still will have to deal with the ruling-party majority. Already, Prime Minister Carlos Gomes, a member of the PAIGC ruling party, has said he would not step down and would have to rule alongside Mr. Vieira.

"Although he has significant support within the ruling party, its by no means unanimous," Mr. Melville said.

Guinea-Bissau has been plagued by coups and instability since its independence from Portugal in 1975. Mr. Vieira ruled Guinea-Bissau with an iron fist from 1980 until 1999, when he was overthrown in a bloody civil war.