By Muchena Zigomo

HARARE (Reuters) - Jacob Zuma, leader of the ruling party in Zimbabwe's powerful neighbour South Africa, has joined a chorus of demands for the release of delayed results from a presidential election 11 days ago.

Zimbabwe's opposition Movement for Democratic Change says its leader, Morgan Tsvangirai, won the vote and should be declared president immediately, ending 28 years of rule by Robert Mugabe.

But Mugabe and his ZANU-PF party are trying to delay an announcement pending a recount. The MDC has asked the High Court to order the outcome to be announced.

The MDC says Mugabe, accused by critics of ruining his once prosperous country, has unleashed a wave of violence against the opposition since the March 29 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."

Western powers led by former colonial ruler Britain and the United States have been calling for the result since last week but South Africa has much greater influence as the regional power that has tried to mediate in the Zimbabwe crisis.

"It is not a good thing to keep the nation in suspense. Now the Zimbabwean elections have become an international issue. We all expected that once the elections were finished, results would be announced. Now there are suspicions from the people," said Zuma, who met Tsvangirai earlier this week.

His remarks opened a gap with Mbeki who has consistently called for "quiet diplomacy" in Zimbabwe and led unsuccessful mediation last year by the regional body SADC.

Zuma ousted Mbeki as party leader in December and has gradually begun to eclipse him since then.

TENSION

Mugabe's critics blame him for reducing the population to misery by mismanagement that has wrecked the Zimbabwean economy, now suffering the world's highest hyper-inflation, chronic shortages of food and fuel and a near worthless currency.

He says Western sanctions are to blame.

The long delay in issuing results has raised tensions in Zimbabwe and fuelled opposition accusations that Mugabe is planning a violent backlash to stay in power.

Mugabe suffered his first defeat in a parallel vote on March 29 when ZANU-PF lost control of parliament.

MDC Secretary-General Tendai Biti said on Tuesday Mugabe was trying to prolong the delay in results to push opposition supporters into violence and give himself a pretext to declare a state of emergency.

"I say to my brothers and sisters across the continent -- don't wait for dead bodies in the streets of Harare. There is a constitutional and legal crisis in Zimbabwe," he said.

Biti said Mugabe was trying to rig the result so he could contest a runoff against Tsvangirai after cowing opposition supporters with his loyal militias.

A farmers' union said independence war veterans, used as political shock troops by Mugabe, had evicted more than 60 mostly white farmers from their land since the weekend.

Zimbabwe state television said Tuesday night that war veterans had occupied 11 farms in the northeastern part of the country.

South African Nobel peace prize laureate Archbishop Desmond Tutu called on Mugabe to accept that he lost the presidential election and step down to ease tensions. He said in San Francisco that peacekeepers may be needed to help restore order.

The High Court ruled on Tuesday it would urgently consider the MDC application to force release of the election results. The case was continuing on Wednesday.