Zimbabwe's President Robert Mugabe, defiant despite growing African condemnation of his re-election, said on Friday the opposition must drop its claim to power and accept that he was the rightful head of state.

As Mugabe struck an intransigent stance, both Nigeria and Botswana rejected his re-election because of pre-poll violence which the opposition says killed 103 of its supporters.

Mugabe returned home from Egypt on Friday after an African Union summit earlier in the week which handed him an unprecedented rebuff, saying he should negotiate a national unity government with Morgan Tsvangirai's MDC opposition.

He told thousands of cheering supporters at the airport: "Tsvangirai and his group must disabuse themselves of their claim (to power)."

He added: "We are open to dialogue but reality is reality and it has to be accepted... I am the President of the Republic of Zimbabwe."

Mugabe extended his 28-year rule in a June 27 election which Tsvangirai boycotted, saying a violent, government-backed campaign made a fair vote impossible.

Nigeria, Africa's most populous nation, expressed strong displeasure at both the violent campaign and its result.

"We therefore do not consider the outcome of that election as a basis for moving forward," Foreign Minister Ojo Maduekwe told reporters.

Botswana called on the Southern African Development Community, the regional body mediating in Zimbabwe, not to recognise the former guerrilla commander's election.

Botswana, which neighbours Zimbabwe, was one of the most outspoken critics of Mugabe, 84, at the summit.

Tsvangirai's Movement for Democratic Change (MDC) said on Friday a violent crackdown by security forces and pro-Mugabe militias had killed 103 of its followers while 1,500 had been detained.

Some 5,000 others, including polling agents, were missing after being abducted by ruling ZANU-PF militia or security agents since Tsvangirai defeated Mugabe in a first round of voting in March.

Mugabe remained defiant.

In remarks apparently aimed at Botswana and Zambia, another regional critic, Mugabe said: "If there are some who may want to fight us, they should think twice. We don't intend to fight any neighbours. We are a peaceful country, but if there is a ...neighbouring country that is itching for a fight, ah, then let them try it."

ECONOMY RUINED Mugabe, in power since 1980, insisted that Zimbabwe's crisis, which has ruined the economy and sent millions of refugees into neighbouring states, must be settled internally.

"We are happy that the AU accepted the position that the Zimbabwean problem must be resolved by Zimbabweans through negotiations," he said.

Tsvangirai has rejected talks until violence ends. He says Mugabe's ZANU-PF party must accept him as the rightful election winner, after a first round poll in March in which he defeated the veteran president.

Tsvangirai's MDC said that not a single member of ZANU-PF had been arrested despite the murder of its supporters.

MDC supporters arrested, on charges of political violence, included 20 legislators or parliamentary candidates, the opposition said in a statement. Members of parliament had been held for "trumped up charges" of inciting violence.

"The regime cannot talk dialogue when it is acting war across the length and breadth of the country," the MDC said.

Botswana noted that Mugabe had ignored appeals from SADC and the U.N. Security Council to call off the election.

"As a country that practises democracy and the rule of law, Botswana does not ... recognise the outcome of the presidential run-off election and would expect other SADC member states to do the same," Botswana's Foreign Minister Phandu Skelemani said.

Mugabe said he wanted South African President Thabo Mbeki to continue mediating in the Zimbabwe crisis, as he has done as the official SADC mediator since last year.

Mbeki has been widely criticised, including inside South Africa itself, for what is seen as ineffective mediation that favours Mugabe. Tsvangirai says he is not satisfied with Mbeki and has called for an AU envoy to lead expanded mediation.

South Africa's Deputy Foreign Affairs Minister, Aziz Pahad, told journalists on Friday Pretoria hoped Mugabe and the opposition were seriously preparing for negotiations on a unity government "despite what they are saying in public."

He said violence must stop to allow dialogue to start.

The U.S. embassy in Harare has found shelter for around 200 victims of the election violence who began camping outside its compound on Thursday, American spokesman Mark Weinberg said.

Women and children were moved to safe houses on Thursday night and Weinberg said about 160 men would be put in the care of U.N. and other international aid organisations.