African pressure mounted on Tuesday for President Robert Mugabe to call off a June 27 election after the UN Security Council issued an unprecedented condemnation of violence against opposition supporters.

But Mugabe remained defiant and said he must fulfil a legal obligation to go ahead with the vote.

"The West can scream all it wants. Elections will go on. Those who want to recognise our legitimacy can do so, those who don't want, should not," Mugabe said.

Both Senegalese President Abdoulaye Wade and South African ruling ANC leader Jacob Zuma said the presidential run-off must be postponed after opposition leader Morgan Tsvangirai withdrew from the vote and fled to the Dutch embassy in Harare.

Wade said in a statement that Tsvangirai took refuge after being tipped off that soldiers were on the way to his house. "He is only safe because, alerted by friends, he left in a hurry a few minutes earlier," Wade said.

Mugabe said at a rally in western Zimbabwe that Tsvangirai was not in danger. "Tsvangirai is frightened. He has run to seek refuge at the Dutch embassy. What for? These are voters, they will do you no harm. Political harm, yes, because they will vote against you. No one wants to kill Tsvangirai".

Zuma, who rivals President Thabo Mbeki as South Africa's most powerful man, called for urgent intervention by the UN and regional body SADC (Southern African Development Community), saying the situation in Zimbabwe was out of control.

"The ANC (African National Congress)  says the run-off is no longer a solution, you need a political arrangement first ...then elections down the line," Zuma said.

Mugabe said he would not refuse to negotiate with Tsvangirai but Friday's vote could not be called off. "For now there is only one thing for us to accomplish...it's the legal process on the 27th of June," the 84-year-old president said.

US ambassador to Zimbabwe, James McGee, said the world could do nothing to stop Friday's vote. He called on SADC to declare both Mugabe and the election illegitimate. - Reuters