Opposition leader Morgan Tsvangirai accused President Robert Mugabe of forcing Zimbabweans to vote on Friday in an election in which the 84-year-old leader is the only candidate.

Mugabe, in power for 28 years, went ahead with the vote despite a wave of international condemnation after Tsvangirai withdrew because of state-backed violence against his supporters.

Tsvangirai, who has taken refuge in the Dutch embassy for the last six days, told a news conference millions of people were staying away from the polls despite intimidation. He returned to the embassy after speaking.

"What is happening today is not an election. It is an exercise in mass intimidation with people all over the country being forced to vote," Tsvangirai said.

The opposition says almost 90 of its supporters were killed.

Turnout was low in urban areas where Tsvangirai's Movement for Democratic Change is traditionally strong. But it was not clear how many voters went to the polls in rural districts.

Tsvangirai, calling the poll a farce, earlier urged people to abstain but said they should vote if they were in danger.

"Whatever might happen, the results.will not be recognised by the world. No matter what you are forced to do, we know what is in your heart. Don't risk your life. The people's victory may be delayed but it won't be denied," he said in a statement.

Voting began shortly after 6 a.m. British time and turnout was much lower in urban areas than in parliamentary and presidential elections in March, when people queued from the early hours. Polling was due to end at 6 p.m. British time.

Tsvangirai won the March 29 poll but fell short of the majority needed for outright victory.

DREAM

The G8 group of rich nations lambasted Zimbabwe for going ahead with the run-off and the United States said the U.N. Security Council may consider fresh sanctions next week.

Tsvangirai said he understood South African President Thabo Mbeki planned to recognise Mugabe's re-election. But he said it would be a "dream" to expect his MDC to join a national unity government with Mugabe's ZANU-PF.

Mbeki, the designated regional mediator in Zimbabwe, has been widely criticised for a soft approach towards Mugabe despite an economic crisis that has flooded South Africa and other countries with millions of refugees.

Tsvangirai said voters were being ordered to record the serial numbers of their ballot papers to identify how they cast their ballots. Pro-Mugabe militias had threatened to kill anybody abstaining or voting for the opposition, he said.

Voters had their little finger dyed with purple ink.

"There is no doubt turnout will be very low," said Marwick Khumalo, head of monitors from the Pan African Parliament.

But state television denounced foreign media reports of low turnout. It showed long queues in a semi-rural constituency close to Harare and said voters ignored MDC appeals to abstain.

Another African election monitor, who asked not be to named, said turnout was low except in some ZANU-PF strongholds.

Mugabe voted with his wife at Highfield Township, on the outskirts of Harare. Asked how he felt, he told journalists: "Very fit, optimistic, upbeat," before being driven away.

In the affluent Greendale suburb of Harare in the morning there were scores of people queuing for bread at a shopping centre but only 10 at a polling station nearby.

"I need to get food first and then maybe I can go and vote.I heard there could be trouble for those who don't," said Tito Kudya, an unemployed man.

Mugabe has presided over an economic collapse accompanied by hyper-inflation, 80 percent unemployment, food and fuel shortages.

A loaf of bread now costs 6 billion Zimbabwe dollars, or 150 times more than at the time of the first round of elections.

Khumalo said his observers had seen a very long queue in the morning but it turned out to be people lining up for bread.

"The ingredients that would make this election free and fair, we haven't seen them yet," he told BBC television.

A middle-aged man waiting for a bus said it was dangerous to talk about politics. "Your tongue can cost you your teeth," he told Reuters, adding that he would vote.

"I hope that will mean the trouble that we have been seeing also goes away," he said.

Analysts said Mugabe was pressing ahead with the election to try to cement his grip on power and strengthen his hand if he was forced to negotiate with Tsvangirai.

The Zimbabwe Electoral Commission said the vote was going well. "Everything is well on course and people are voting peacefully," Deputy Chief Elections officer Utoile Silaigwana told state radio.

The vote has been widely condemned both inside and outside Africa.

African Union foreign ministers were discussing Zimbabwe ahead of a summit in Sharm el-Sheikh, Egypt. "I don't think we are going to accept the result but we are still discussing," one minister said, asking not to be identified.

A security committee of the Southern African Development Community (SADC) called earlier this week for the vote to be postponed, saying Mugabe's re-election could lack legitimacy.

But Mugabe, who thrives in defiance, remained unmoved and said he would attend the AU summit to confront his opponents.

Mugabe says he is willing to sit down with the MDC but will not bow to outside pressure.

U.S. Secretary of State Condoleezza Rice said after a Group of Eight nations (G8) meeting in Japan that Washington would raise the issue of further sanctions at the U.N. Security Council. The European Commission described the run-off as "a sham".