Zimbabwean police detained Morgan Tsvangirai, the opposition leader, today at a roadblock during campaigning for the country's run-off presidential vote, his spokesman said.

Mr Tsvangirai, who will face Robert Mugabe in the June 27 contest, was stopped by police in southwestern Zimbabwe at around 1000GMT and detained along with his entourage.

“We are currently held up. They are saying there’s a commanding officer whom we should wait for. They are not saying why they are holding us up," said Mr Tsvangirai’s spokesman, George Sibotshiwe.

"It’s not an arrest but illegal detention. It appears they want to disrupt our campaign programme."

MDC officials said that Mr Tsvangirai had been taken to a charge office in the town of Lupane along with his bodyguards and senior aides.

The police action follows the official banning of large-scale rallies for the MDC leader, which have forced him into a meet-and-greet style of campaigning. Mr Tsvangirai returned to Zimbabwe two weeks ago after a month abroad, spent mostly in Botswana and South Africa.

The MDC ended Mr Mugabe's Zanu (PF) party's 28-year reign in parliament in March elections and claims that Mr Tsvangirai won the presidential contest by a narrow majority. After a lengthy delay in announcing the result, however, electoral officials called a run-off vote.

Since then, Zanu (PF) has been accused of a campaign of violence that its critics say is aimed at intimidating MDC voters. The MDC says that more than 50 of its supporters have been killed and thousands driven from their homes, especially in rural areas.

Yesterday, the MDC alleged that soldiers and Zanu (PF) activists had beaten and threatened to shoot Zimbabweans who wanted to meet and support Mr 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,” Mr Tsvangirai said while campaigning in Bulawayo.

Meanwhile, the day after Mr Mugabe spoke at a world summit against hunger in Rome - at which he blamed Britain for Zimbabwe's food shotages - the New York-based group Human Rights Watch accused him of imposing control over food aid to intimidate voters before the presidential vote.

“The decision to let people go hungry is yet another attempt to use food as a political tool to intimidate voters ahead of an election,” said Tiseke Kasambala, Zimbabwe researcher at Human Rights Watch. “President Mugabe’s government has a long history of using food to control the election outcome.”

Many Zimbabweans, particularly in rural areas, rely on food aid due to shortages of basic commodities such as cooking oil and cornmeal and rampant inflation, yet The Mugabe government has ordered aid groups including Save the Children UK, CARE International and ADRA to stop work in the country immediately.

“If we continue like this, we are going to have a crisis,” said Cephas Zinhumwe, who heads an umbrella group for non-governmental organisations. “The situation is ugly."

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