Mwanawasa, who chairs the Southern African Development Community, said in Lusaka the crisis required a concerted effort by all southern African countries to find a solution. It was the first move by Zimbabwe's neighbours to intervene after the March 29 elections. The presidential result is still not known.

A lawyer for Zimbabwe's electoral commission said on Wednesday it would be "dangerous" for the High Court to order the release of presidential election results, as demanded by the opposition MDC.

The Movement for Democratic Change has gone to court to try to force out the result of the March 29 vote, saying its leader Morgan Tsvangirai has won and should be declared president, ending the 28-year rule of President Robert Mugabe.

Mugabe is trying to delay the result announcement, pending a recount, to give him time to prepare for a probable runoff against Tsvangirai.

George Chikumbirike, a lawyer for the Zimbabwe Electoral Commission, told judge Tendai Uchena: "It would be dangerous in my view to give an order because it might not be complied with ... because of outside exigencies which the party (ZEC) will be unable to control."

He did not elaborate but appeared to be referring to rising tension in Zimbabwe because of the post-election impasse.

Chikumbirike also declined to say how far the ZEC had gone in preparing to announce the result, saying this was privileged information which "the commission has entitlement to release when it's ready".

Jacob Zuma, leader of the ruling party in Zimbabwe's powerful neighbour South Africa, earlier joined a chorus of demands for the release of the results.

Zimbabwe's third presidential candidate, ruling party defector Simba Makoni also urged the urgent release of the outcome. In Brussels, European Commission President Jose Manuel Barroso voiced concern at the delay.

The MDC says Mugabe has unleashed a wave of violence against the opposition since the election and called on African nations to intervene to prevent further bloodshed.

Zuma, who rivals President Thabo Mbeki as the most powerful man in South Africa and is the frontrunner to succeed him in 2009, told the Star newspaper: "I think the Zimbabwe Electoral Commission should have announced results by now."