HARARE, Zimbabwe — A mob believed loyal to President Robert Mugabe assaulted a convoy of U.S. and British diplomats Thursday, and the government ordered aid groups to halt operations in a move that could hamper food deliveries in impoverished Zimbabwe.
The U.S. Embassy said a group of Zimbabwe "war veterans," often violent Mugabe loyalists, waylaid a convoy of American and British diplomats Thursday, beating a local staffer, slashing tires and threatening to burn the envoys.
The diplomats were looking into political violence before a presidential election runoff, and the incident was the latest sign of how tense Zimbabwe is as Mugabe prepares to face an opposition leader who led voting in the first round.
Opposition and human rights groups accuse Mugabe of orchestrating violence to ensure he wins re-election amid growing unpopularity for his heavy-handed rule and the country's economic collapse. Police held the president's runoff rival, Morgan Tsvangirai, for nine hours Wednesday.
Late Thursday, the government ordered aid groups to halt operations in Zimbabwe. Millions of Zimbabweans depend on food handouts from such groups as well as Mugabe's government as the economy crumbles.
The suspension decree came a day after Human Rights Watch accused the government of moving to impose control over food aid as a way to intimidate voters before the runoff.
In his order, social welfare minister Nicholas Goche said he had learned that aid groups were violating terms of their agreement with the government.
He did not elaborate, but prior to his order there was already concern about a potentially worsening food supply. Earlier this week the aid organization CARE International said it had been ordered to halt its operations pending an investigation of allegations that its workers were campaigning for the opposition. CARE denied the allegation. And other aid groups had been told to curb activities.
CARE alone says it provides aid to about 500,000 Zimbabweans and had been scheduled to expand food distribution to about 1 million people this month.
Officials in Washington and London said the diplomats were returning from a trip to investigate violence in northern Zimbabwe when they were stopped at a roadblock on the outskirts of Harare, the capital. The convoy was halted for some six hours before it was allowed to drive on.
U.S. Ambassador James McGee, who was not with the convoy, said police and military officers detained the diplomats in an "illegal action." He said they were assisted by a crowd of "war veterans," a group whose members purportedly fought in Zimbabwe's independence war and are Mugabe's fiercest and most violent supporters.
"The war veterans threatened to burn the vehicles with my people inside unless they got out of the vehicles and accompanied the police to a station nearby," McGee told CNN.
A spokesman for the U.S. Embassy, Paul Engelstad, told The Associated Press that some in the throng beat one of the embassy's Zimbabwean employees and slashed the tires of some cars in the convoy.
McGee said five Americans, four Britons and three Zimbabwean employees were traveling in three cars.
The U.S. government said it would take the incident to the U.N. Security Council.
"It is absolutely outrageous, and it is a case of the kind of repression and violence that this government is willing to use against its own people," State Department spokesman Sean McCormack said of Mugabe's regime.
British Foreign Secretary David Miliband said the attack on British and American diplomats underlined the hardships facing ordinary Zimbabweans under Mugabe's regime _ a life "marked by brutal intimidation, by torture ... and by death."
"We have to be concerned obviously about British staff," he said, "but we also have to be concerned that intimidation does not become the order of the day" ahead of the presidential runoff scheduled for June 27.
Police spokesman Wayne Bvudzijena denied security agents had threatened the diplomats. He said police at the scene intervened to rescue the diplomats from a threatening mob.
"It's unfortunate when diplomats behave like criminals and distort information," Bvudzijena said. "It is a very sad situation."
McGee said Zimbabwean officials had been informed about the trip as required.
Deputy Information Minister Bright Matonga said that while the U.S. ambassador had submitted the necessary documents, the British government had not.
Matonga also accused the diplomats of handing out election materials supporting the opposition.
Mugabe frequently accuses Britain and the United States of plotting to topple him and return Zimbabwe to colonial rule.
In mid-May, McGee led a similar convoy that was briefly stopped at a police roadblock. At one point, a police officer threatened to beat one of McGee's senior aides and then got into his patrol car and lurched it at McGee after the ambassador demanded the officer's name.
Mugabe has led Zimbabwe since independence from Britain in 1980 and was once hailed as a liberator who promoted racial reconciliation and economic empowerment.
But he has been accused of clinging to power through election fraud and intimidation. His order for the seizure of white-owned farms beginning in 2000 has been blamed for a slump in Zimbabwe's once-thriving agricultural industry that has plunged the country into economic collapse.
Discontent propelled the main opposition leader, Tsvangirai, to the top in presidential voting March 29. But while he got the most votes of the four candidates, he did not win the 50 percent plus one vote needed to avoid a runoff with Mugabe, who finished second.
Police hauled Tsvangirai off into custody Wednesday and held him nine hours at a police station in southern Zimbabwe, his party said. But he resumed campaigning Thursday.
In a message to Zimbabweans, Tsvangirai said his detention was "nothing compared to the hardships millions of Zimbabweans have had to endure."
"Today I am saying to the nation that the rebuilding of our beautiful country must begin now," he added. "The time of intolerance and destruction must end. The time for peace and prosperity begins with each one of you voting."
Tsvangirai said in an interview that he was campaigning in an environment "meant to frustrate the opposition. But we are inspired by the enthusiasm of people who we are meeting on the ground."
Rights activists said Thursday that suspected Mugabe supporters fire-bombed an office of Tsvangirai's Movement for Democratic Change in the southern province of Masvingo on Wednesday, killing at least two party officials. The party says at least 60 of its supporters have been slain the past two months
The national elections in March were a blow to Mugabe. In addition to trailing in the presidential ballot, he saw his ZANU-PF party lose its majority in parliament for the first time since independence as Tsvangirai's party won control of the body.
Tsvangirai, who lost a 2002 presidential election that independent observers said was rigged in Mugabe's favor, had only returned to Zimbabwe in late May to campaign for the runoff. He left the country soon after the March first round, and his party has said he was the target of a military assassination plot. He has survived at least three assassination attempts.
In New York, United Nations officials said Secretary-General Ban Ki-moon had gotten Mugabe's permission to send his assistant secretary-general for political affairs to help Zimbabwe try to hold a free and fair runoff.
Ban plans to send Haile Menkerios, a Harvard-educated diplomat and former Eritrean ambassador, to Zimbabwe within days, as soon as Menkerios obtains a visa.