He promptly vowed to accelerate his controversial programme of land reform and said his victory was a triumph against "British imperialism".

I, Robert Gabriel Mugabe, do swear that I'll be faithful and bear true allegiance to Zimbabwe and observe the laws of Zimbabwe, so help me God

Robert Mugabe

"The land reform programme must proceed with greater speed and strength, so the losses and drawbacks of the current drought-ridden season can be overcome," he said.

Mr Mugabe used the promise of redistributing land to poor, black farmers as an election rallying call, and he had been expected to accelerate the programme to reward his supporters.

Sunday morning's inauguration ceremony, which included a 21-gun salute and military fly-past, was boycotted by EU countries, the US and some members of the Commonwealth.

These countries, along with local pro-democracy groups and Mr Mugabe's rival, Morgan Tsvangirai, have said the election was flawed and unacceptable.

But many African states have endorsed 78-year-old Mr Mugabe's victory.

South African Deputy President Jacob Zuma congratulates Mr Mugabe

The presidents of Tanzania, Zambia, Mozambique, Malawi and the Democratic Republic of the Congo were at the ceremony in the capital, Harare.

The leaders of South Africa and Nigeria - the continent's two most powerful countries - did not attend, but are expected in Harare for separate meetings with Mr Mugabe and opposition leader Morgan Tsvangirai on Monday.

They will be trying to negotiate some sort of political compromise ahead of the Commonwealth meeting in London on Tuesday, which is due to consider Zimbabwe's suspension.

Speaking out

Mr Mugabe, speaking in public for the first time since his election victory, used his inauguration address to attack former colonial power, Britain.

"You certainly have been able to see how Britain and its white allies have blatantly sought to ensure that this last presidential election be won by their prot�g� and yet not by me," he told the audience.

But South African President Thabo Mbeki said on Saturday that, while Zimbabwe's fate would have to be decided by Zimbabweans, the outside world did have a right and duty to speak out about what was happening there.

The opposition accuses Mugabe supporters of reprisal attacks

South Africa would not take an independent position, he said, but would consult various other bodies, including the South African Development Community (SADC), the Organisation of African Unity and the Commonwealth.

SADC and the OAU have both expressed the belief that the election was substantially free and fair, in contast with the Commonwealth, which said the poll did not adequately allow the electors to express their will.

South Africa's position on Zimbabwe is particularly important, partly because it has political weight and economic leverage - it is the most powerful economy in southern Africa and it supplies Zimbabwe's fuel and power.

Reprisal attacks

The opposition in Zimbabwe has accused Mr Mugabe's supporters of stepping up reprisal violence against its activists.

In the past two days, five houses were damaged in the village of Zhombe, 220 kilometres (140 miles) southwest of Harare, Learnmore Jongwe, an opposition lawmaker, told the Reuters news agency.

"There is retribution through assaults and threats," he said.

Militants have also ordered 15 white farmers to leave their homes since Wednesday, because they had provided logistical support for opposition campaigners, the Commercial Farmers Union said.