Tendai Biti of Zimbabwe's main opposition Movement for Democratic Change (MDC), surrounded by police officers, walks past a prison vehicle, as he was given bail at the Harare Magistrates Court. Picture: Jekesai Njikizana/AFP

Harare - Western governments and the UN expressed alarm on Thursday as top Zimbabwe opposition figure Tendai Biti appeared in court after a dramatic attempt to flee to neighbouring Zambia and claim asylum.

Biti, a veteran figure in the opposition Movement for Democratic Change (MDC), was taken handcuffed into a courtroom in Harare under a heavy police presence to face charges of public violence as well as the illegal declaration of election results.

"We survive," Biti said after he was released on bail of $5,000 (4,330 euros) on the condition that he surrenders his passport and does not address any political gatherings or news conferences.

"It's a pity that in most of Africa we don't respect the rule of law," added Biti, an internationally-respected finance minister in Zimbabwe's 2009-2013 power-sharing government.

Biti made a dash across the border on Wednesday, facing allegations of inciting protests last week by proclaiming victory for the opposition in Zimbabwe's first elections since the downfall of Robert Mugabe in November.

Mugabe's successor at the head of ruling party ZANU-PF, Emmerson Mnangagwa, was later declared the winner according to the official results, but the MDC claims the election was rigged.

Zambian authorities rejected Biti's plea for political asylum and handed him back to Zimbabwean police on Thursday morning, in defiance of a Zambia court ruling, according to his lawyers. 

Tendai Biti speaks to the press after being released on bail. Picture: Jekesai Njikizana/AFP

The UN refugee agency said it was "gravely concerned" that Biti had been deported while trying to claim asylum.

"Forcibly returning refugees and asylum-seekers to their country of origin is a serious violation of international refugee law," the UNHCR said in a statement.

It urged Zambia to investigate the incident, which comes after accusations that Zimbabwe's authorities are pursuing a heavy crackdown on the opposition as it pursues its claims of electoral fraud.

Zambian government spokeswoman Dora Siliya said authorities had only received the ruling from its own court blocking Biti's expulsion after he had been returned.

"His asylum was denied on the basis that in his country there is no breakdown in the rule of law," she told AFP, adding that Biti himself was "running away from the due process of the law" as he was wanted by authorities.

Western nations said they were "deeply disturbed by continuing reports that opposition supporters are being targeted by members of the Zimbabwean security forces".

In a joint statement, the EU, US, Canadian and Australian missions to Zimbabwe urged authorities to guarantee Biti's safety and human rights.

Biti is accused of encouraging protests on August 1, when opposition demonstrators took to the streets in Harare angrily claiming ZANU-PF had stolen the election.

Troops opened fire on the protesters, killing six people and sparking an international outcry.

Mnangagwa wrote on Twitter that Biti was released after he intervened personally in the case.

"At such a crucial time in the history of the new Zimbabwe, nothing is more important than unity, peace and dialogue," he posted.

"Equally important, however, is an adherence to the rule of law," he said, adding that proceedings against Biti would continue "due to the serious nature of the allegations".

Mnangagwa, who is seeking to reverse Zimbabwe's economic isolation and attract desperately needed foreign investment, had vowed the elections would turn a page on Mugabe's repressive 37-year rule. 

But the aftermath of the polls has been marred by allegations by rights groups as well as the MDC of a crackdown on opposition members, including beatings and arrests.

MDC leader Nelson Chamisa has vowed to launch a legal challenge against the results, and must do so by Friday.

Mnangagwa won the July 30 election with 50.8 percent of the vote - just enough to avoid a run-off against Chamisa, who scored 44.3 percent.

The Zimbabwe Election Commission - synonymous with fraud under Mugabe -  insists the elections were free and fair this time around.

International monitors praised the conduct of the election itself, although EU observers said Mnangagwa benefited from an "un-level playing field" and a degree of voter intimidation.