The leader of Zimbabwe's opposition party has postponed his return home after his party said it had discovered an assassination plot against him.

A spokesman for the Movement for Democratic Change said Saturday it received information from a "credible source" about an assassination plot against Morgan Tsvangirai.

The spokesman refused to say whether Zimbabwean government officials were implicated in the plot.

He said the government has refused to take threats against Mr. Tsvangirai seriously and said the opposition is working with regional leaders instead of the government to try to ensure Mr. Tsvangirai's protection.

Mr. Tsvangirai has been out of Zimbabwe since shortly after the March 29th presidential and parliamentary elections. Official results show him beating President Robert Mugabe, but falling short of the majority needed to avoid a run-off election.

The opposition leader had been due to return to Zimbabwe from South Africa Saturday to begin campaigning for the second round vote, which has been scheduled for June 27th.

Opposition officials say a large campaign rally in the city of Bulawayo will go ahead Sunday regardless of whether or not Mr. Tsvangirai can attend.

The MDC and human rights groups say Mr. Mugabe's supporters are conducting a terror campaign against the president's political opponents. The party says more than 30 of its activists have been killed since the first round of voting on March 29th.

Mr. Mugabe's ruling ZANU-PF party and government officials reject the allegations and accuse the MDC of fomenting the violence.

Mr. Mugabe has led Zimbabwe since the country won independence in 1980.