HARARE, Zimbabwe - Zimbabweans voted Saturday on whether to keep the ruler blamed by opponents for their country's economic collapse, though President Robert Mugabe's challengers claimed the election was rigged even before the polls opened.
The main opposition party said it was investigating reports of thousands of voters being turned away from polls and the discovery of stuffed ballot boxes in one district. African observers also questioned thousands of names on official rolls.
The election presented Mugabe with the toughest political challenge to his 28-year rule. He dismissed allegations that the vote was rigged to keep him in power.
"I cannot sleep with a clear conscience if there is any cheating," Mugabe, 84, said after voting and promising to respect results. "If you lose an election and are rejected by the people, it is time to leave politics."
Voting was generally peaceful, with Zimbabweans standing in lines for hours. Preliminary results are expected by Monday. If no candidate wins 50 percent plus one vote, there will be a runoff.
Running against Mugabe are opposition leader Morgan Tsvangirai, 55, who narrowly lost disputed 2002 elections, and former ruling party loyalist and finance minister Simba Makoni, 58.
Makoni's defection is a sign of growing dissent within Mugabe's ruling Zimbabwe African National Union party. But while he could take support from Mugabe, Makoni also could divide the opposition vote.
Opposition leaders accuse Mugabe of dictatorship and destroying the economy. Mugabe calls his opponents stooges of former colonial ruler Britain and says the nation must make sacrifices to overcome its colonial legacy.
The economic collapse of Zimbabwe has dominated the campaign. The nation once fed itself and helped feed its neighbors, but now a third of its population depends on international food handouts and remittances from relatives abroad.
Unemployment stands at 80 percent — the same percentage that survives on less than $1 a day. Inflation is the highest in the world at more than 100,000 percent and people suffer crippling shortages of food, water, electricity, fuel and medicine.
In southern Bulawayo, an opposition stronghold, 78-year-old Moffat Simon Mabhena was among many who lined up to vote hours before dawn.
"We want to see change in this country," Mabhena said. "I want to see Robert Mugabe out."
Zimbabwe barred several international media organizations from its elections as well as observers traveling from the United States and the European Union.
"There are a lot of big question marks hanging over this election in terms of the integrity of the electoral process," U.S. State Department spokesman Sean McCormack said Friday.
An observer from the Pan-African Parliament said the longest lines in Harare on Saturday were at two polling stations on the edge of a vacant plot where 8,450 people had registered as residents.
The observer, who spoke on condition of anonymity because he was not authorized to speak to the media, gave an Associated Press reporter a letter to the Zimbabwe Electoral Commission asking for an explanation.
A parliamentary candidate for Mugabe's party in Bulawayo, Judith Mkwanda, reported two explosions outside her home that shattered windows just after midnight. Police said it was firebombed. No injuries were reported.
Tsvangirayi's party said the home of one of its agents was set ablaze Saturday in northeast Zimbabwe.
The independent Zimbabwe Election Support Network's monitors reported a heavy police presence at polling stations, ostensibly to help illiterate voters and allowed under a belated presidential decree that breaks an agreement signed with the opposition. The opposition said it was intimidation.
Tendai Biti, a senior official in Tsvangirai's party, told reporters that his party's agents reported 200 voters — more than half of those who had cast votes in that polling place — were assisted by police in an area where the illiteracy rate was closer to 10 percent.
Biti said opposition party agents had been barred from polling stations in several districts and that thousands of voters were turned away because their names were not on voters' rolls or on flimsy excuses about identification particulars.
His party also was investigating a report that six stuffed ballot boxes were found before voting got under way in one district, Biti said.
Fighter jets were sent screaming over some districts in opposition strongholds in what Biti called another sign of intimidation.
On Friday night, monitors from the 14-nation Southern African Development Community said they had observed "a number of matters of concern," which they did not identify.
Some 9,000 polling stations were set up for 5.9 million registered voters, the official count. But Biti said the real number was nearer 3.5 million because the rolls were inflated with names of dead or fictitious people, and economic and political refugees who left the country.
Zimbabweans had 12 hours to cast ballots, voting in a single day for the first time for president, 210 legislators, 60 senators and 1,600 local councilors.
After independent monitors said 2002 elections were rigged, Western nations imposed visa bans and froze bank accounts for Mugabe and 100 of his cronies, but Mugabe has convinced many supporters that those limited sanctions are to blame for the country's woes.
Zimbabwe's economy began unraveling when Mugabe ordered the often-violent eviction of white farmers to hand land over to blacks — mostly his relatives, friends and allies. Nevertheless, the land campaign won him support among many Zimbabweans