Police released Zimbabwe's opposition leader Morgan Tsvangirai on Wednesday after holding him for more than eight hours, his lawyer and party officials said.

Tsvangirai was detained shortly after noon as he campaigned for a presidential election run-off, along with the vice president and chairman of his Movement for Democratic Change (MDC), the party said.

"They've just been released without charge. The police were saying he addressed an unsanctioned meeting...They were held for 8 hours before their release," Tsvangirai's lawyer Job Sibanda said.

The MDC said Tsvangirai's four-vehicle convoy was stopped at a roadblock manned by police and members of President Robert Mugabe's feared Central Intelligence Organisation. He was held at a rural police station southwest of Harare.

"It appears they want to disrupt our campaign programme," said Tsvangirai's spokesman, George Sibotshiwe.

Tsvangirai, who has been arrested several times in the past, defeated Mugabe in a March 29 presidential election but failed to win the absolute majority needed to avoid a second ballot. The run-off is scheduled for June 27.

In March last year, Tsvangirai was detained and badly beaten in police custody after he tried to attend a banned anti-government rally in Harare.

Mugabe's vow never to allow the MDC to take power has stoked opposition fears that the ruling ZANU-PF will use intimidation and vote-rigging to extend the president's 28-year rule.

The United States said Tsvangirai's detention was deeply disturbing.

"He should be released immediately, unharmed, untouched," State Department spokesman Sean McCormack said in Washington.



"WAR ZONE"

The opposition says 65 people have been killed by Mugabe's supporters since the election. On Wednesday it said soldiers and ZANU-PF activists had beaten and threatened to shoot Zimbabweans who wanted to support Tsvangirai.

"Mugabe is determined to turn the whole country into a war zone in order to subvert the will of the people and steal the June 27th election by any means possible," Tsvangirai said while campaigning in Bulawayo before he was held by police.

Mugabe says the opposition is responsible for violence.

The government confirmed that it had suspended the operations of aid agency CARE International and other humanitarian groups, saying they had become involved in politics and were backing Tsvangirai's campaign.

CARE International has denied the charge.

Deputy Information Minister Bright Matonga said the groups would be allowed to resume their work if they avoided politics.

"They must choose between politics and genuine humanitarian work," he said.

U.S.-based Human Rights Watch accused Zimbabwe of using food as a political weapon, while the United States said the suspension would mean that more than 100,000 Zimbabweans would go hungry this month.

Speaking in Rome, U.N. High Commissioner for Human Rights Louise Arbour said she was deeply concerned by the reports: "To deprive people of food because of an election would be an extraordinary perversion of democracy, and a serious breach of international human rights law."

EU foreign policy chief Javier Solana said Tsvangirai's arrest heightened "further the fears of the Zimbabwean people and the international community about the conditions under which the poll will be held."

Zimbabwe's agricultural sector has collapsed since 2000, when Mugabe's government began seizing white-owned farms as part of a land redistribution policy designed to help poor blacks.

Zimbabwe now suffers chronic food shortages and relies on imports and foreign aid to feed its people. Mugabe blames the economic collapse on sanctions imposed by enemies in the West.