President Robert Mugabe's (search) ruling party has secured a majority in parliament, according to results announced Friday in an election the opposition says was marred by fraud.

Thursday's vote was seen as a test of the legitimacy of Mugabe's increasingly autocratic regime after 25 years in power. Mugabe, one of Africa's longest-serving leaders, is the last on the continent who has ruled his country since independence from the colonial powers.

Mugabe's Zimbabwe African National Union-Patriotic Front (search) won 55 of parliament's 120 elected seats, compared to 34 for the main opposition Movement for Democratic Change (search). Mugabe appoints an additional 30 seats, guaranteeing a majority for his party.

Opposition party leader Morgan Tsvangirai (search) had pledged to contest the results, and said he would do more than merely appeal in Zimbabwe's courts — which the government has packed with sympathetic judges. But he would not specify what action it would take.

"The government has fraudulently, once again, betrayed the people," Tsvangirai said at a news conference earlier Friday. "We believe the people of Zimbabwe must defend their vote and their right to free and fair elections."

Previous attempts at protest have been violently crushed by security forces and members of the ruling party's youth militia, and the party has shied away from confrontation in recent years.

Independent Zimbabwean rights groups and the United States, whose diplomats observed the campaign and voting, agreed with Tsvangirai that the polls were flawed. They said that, although this campaign had been relatively peaceful, violence and intimidation in previous years had already skewed the poll in favor of Mugabe's party.

State Department spokesman Richard Boucher, speaking in Washington, said before the final results were released that the balloting had taken place on a "playing field heavily tilted in favor of the government."

In another sign of irregularities, the independent Zimbabwe Election Support Network (search), which deployed 6,000 observers nationwide, said as many as a quarter of those who tried to vote were turned away because their names did not appear on the voter roll, or they failed to present proper identification.

But observers from neighboring countries largely sympathetic to Mugabe said Thursday's poll was conducted in an "open, transparent and professional manner."

A delegation from the 14-member Southern African Development Community (search) — which also endorsed a 2002 presidential poll Western observers said was marred by violence and vote rigging — said they were convinced the count also would be legitimate. But it said it was concerned about the high number of people who were unable to cast ballots.

Mugabe dismissed the opposition's fears of fraud as "nonsense" Thursday, saying: "Everybody has seen that these are free and fair elections."

Early results had shown some success for the MDC because they were released largely from the party's urban strongholds.

"If you look back to the 2000 election, ZANU-PF has a strategy of first announcing election results in MDC strongholds so they can wink at the world and say look how free and fair we are," said party spokeswoman Miriam Mushaye.

Mugabe's nephew, ruling party candidate Patrick Zhawao, was declared the winner in Manyame, 25 miles southwest of Harare, in a what the MDC charged was the first example of vote manipulation by the government.

Election officials announced Thursday night that 14,812 people voted there. But early Friday, they changed the total to 24,000 and said Zhawao got more than 15,000 votes. Election commission officials refused to comment on the discrepancy but dismissed suggestions of vote rigging.

"I won. I was leading. Suddenly I hear about 24,000 votes, and I don't know where the extra 10,000 came from," said losing MDC candidate Hilda Mafudze. "It is the first example of what we are going to start seeing from here on."

Triumphant ZANU-PF supporters carried a mock coffin representing the opposition through the district's Porta Farm village. MDC supporters also marched chanting opposition slogans, but there were no clashes.