(Agencies)
Updated: 2008-03-30 18:23

HARARE - 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.

A Zimbabwean election official holds a candle for a resident (R) to cast her vote at a tented polling station in Harare March 29, 2008. [Agencies]

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.

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.