Zimbabwean opposition leader Morgan Tsvangirai has described the country's election run-off as "an exercise in mass intimidation".

Mr Tsvangirai, who boycotted the poll because of violence, said people across Zimbabwe had been forced to take part and urged the world to reject the vote.

The European Union and the US dismissed the vote as meaningless.

Turnout is reported to have been low. President Robert Mugabe - the only candidate - is assured of victory.

Official results are expected at the weekend.

The Zimbabwe Election Support Network, a monitoring group, reported that people had been forced to vote in most rural areas.

A Zimbabwean journalist said militias loyal to Mr Mugabe had gone door-to-door in townships outside the capital, Harare, to coerce people.

Despite the pressure, Marwick Khumalo, who heads of the Pan-African parliamentary observer mission, told the BBC that overall turnout had been low and the mood sombre.

"We saw one long queue, which we mistook for a polling station, only to find the people were queuing for bread," he said, adding that the ingredients for a free and fair election were missing.

But Justice Minister Patrick Chinamasa told the BBC that people were aiming to preserve Zimbabwe's independence.

"They are voting to say no to the recolonisation of our country," he said.

As he cast his vote in Harare, Mr Mugabe, who is 84, said he was feeling "very fit, very optimistic".

Threat

Foreign ministers for the Group of Eight nations (G8) meeting in Japan have said they could not accept the legitimacy of a government "that does not reflect the will of the Zimbabwean people".

US Secretary of State Condoleezza Rice said they would consult other members of the UN Security Council to see what "next steps" might need to be taken.

The BBC's John Simpson, in Harare despite a reporting ban, says he had never seen an election as frightening - where people know that if they fail to turn out to vote and do not have the ink stain to prove it, they are liable to the most ferocious retribution from the ruling Zanu-PF.

He adds that if someone summoned up the courage to vote for Mr Tsvangirai - whose name is still on the ballot - there were fears their identity could be discovered.

Journalist Themba Nkosi in the southern city of Bulawayo said officials for Mr Tsvangirai's Movement for Democratic Change (MDC) had told supporters in rural areas to vote if they felt their lives were in danger - and to vote for Morgan Tsvangirai or spoil their ballot.

A resident of Manicaland Province told the BBC: "I am not going to vote in a one-person race. I will not vote for a dictator and for hunger while my brother was killed in cold blood."

But Zanu-PF supporter Richard Munsaka, in Hwange, Matebeland North Province said the question of a free and fair election "depends on the eyes of the beholder" and that violence was "not on a massive scale".

Protection

At a news conference held in Harare before polls closed, Mr Tsvangirai said people had been intimidated into voting but said millions had refused.

He called the poll a "sham" exercise staged by a "dictatorship desperate for the illusion of legitimacy".

Mr Tsvangirai also urged the international community to reject the results.

"Anyone who recognises the result of this election is denying the will of the Zimbabwean people," he said.

The MDC leader has been taking refuge at the Dutch embassy for most of the past six days.

Mr Mugabe came second to Mr Tsvangirai in the first round of the presidential vote in March.

Since then, the MDC says some 86 of its supporters have been killed and 200,000 forced from their homes by militias loyal to Zanu-PF.

The government blames the MDC for the violence.

On Friday Zimbabwe was discussed by African Union foreign ministers in the Egypt resort of Sharm el-Sheikh.

Some AU members say the run-off should not have been held, while others, notably South Africa, refuse to criticise Mr Mugabe publicly,

"Our position is that the parties in Zimbabwe should work together," South African Foreign Minister Nkosazana Dlamini-Zuma said.

AU leaders are due to meet on Monday in the resort.

While Mr Mugabe said he planned to attend the summit, he said the AU had "no right in dictating to us what we should do with our constitution, and how we should govern this country".

He has suggested negotiations with the MDC were possible - "should we emerge victorious, which I believe we will".

Mr Tsvangirai has said negotiations would not be possible if Mr Mugabe went ahead with the run-off.