U.S. says Zimbabwe must free Tsvangirai "unharmed"

WASHINGTON (Reuters) - The United States on Wednesday urged Zimbabwe to immediately release opposition leader Morgan Tsvangirai unharmed and said South Africa must use its leverage to pressure President Robert Mugabe.

State Department spokesman Sean McCormack said the detention of Tsvangirai, who heads the Movement for Democratic Change in Zimbabwe, was deeply disturbing.

"He should be released immediately, unharmed, untouched," McCormack told reporters.

Tsvangirai, who was beaten in March last year when he was held in police custody, was picked up at a police roadblock on Wednesday in an apparent attempt to derail his presidential campaign ahead of a run-off vote on June 27.

"There was an incident where he was badly beaten and we would hope and call upon the Zimbabwean government to create an atmosphere in Zimbabwe where those who have political views different than the government can speak out free from fear of intimidation," McCormack said.

Tsvangirai, who has been arrested several times in the past, outpolled Mugabe in a March 29 presidential election but failed to win the absolute majority needed to avoid a second ballot. Mugabe has been in power since independence from Britain in 1980.

The opposition says 50 people have been killed by Mugabe's supporters since the election. On Wednesday it said soldiers and ruling ZANU-PF party activists had beaten and threatened to shoot Zimbabweans who wanted to meet and support Tsvangirai.

McCormack said he did not believe Tsvangirai had been charged with any crime and there was no information about what the government planned to do with him. He was being held at a rural police station southwest of Harare.

He said South Africa's government, which has close historical ties to Harare's ruling ZANU-PF party and has been criticized for being soft on Mugabe, should use its leverage to influence events in Zimbabwe.

"Everybody knows the reality that this government and the leadership of the South African government is uniquely positioned to go to President Mugabe and the leadership there and to encourage them to change their behavior," said McCormack.

"States like South Africa need to use the leverage that they have. It is a tragic situation," said McCormack.

About 4 million Zimbabweans rely on food aid in a country which was once the region's breadbasket but where annual inflation is now a staggering 165,000 percent and unemployment 80 percent.

(Reporting by Sue Pleming, editing by Alan Elsner)