Human Rights Watch has urged the African Union to send election observers and human rights monitors to Zimbabwe immediately to promote peace in the approach to the presidential run-off election scheduled for June 27.

The New York-based watchdog organization warned that unless the current situation in Zimbabwe is reversed, more civilians will be brutalized and killed.

Human Rights Watch accused supporters of President Robert Mugabe's ZANU-PF party, liberation war veterans, the army and police of unleashing a terror campaign in rural areas to punish those suspected of voting for the opposition in the first election round on March 29, and compel support for Mr. Mugabe in the run-off.

South Africa and the Southern African Development Community say they have already sent teams to investigate the violence. South African Deputy Foreign Affairs Minister Aziz Pahad told journalists in Pretoria on Tuesday that Pretoria sent retired generals to investigate the patterns of political violence and determine its source.

He said the military envoys were about to wrap up their investigation.

Pahad said it is imperative that opposition leader and presidential candidate Morgan Tsvangirai of the Movement for Democratic Change be able to return to Zimbabwe.

Tsvangirai's scheduled return Saturday was called off at the last minute by opposition officials who said they had learned of a plot to assassinate him. Later this week the MDC accused military intelligence of mobilizing a squad of snipers to kill him. 

Human Rights Watch Zimbabwe researcher Tiseke Kasambala told reporter Blessing Zulu of VOA's Studio 7 for Zimbabwe that the early deployment of regional monitors will help to tamp down the still-escalating political violence.

U.S. State Department spokesman Sean McCormack said Tsvangirai’s safety is a “real concern" for Washington, and told reporters in a briefing on Monday that Harare's refusal to admit foreign observers for the run-off is also worrisome.

More reports from VOA's Studio 7 for Zimbabwe...