Witnesses described chaos in Harare as riot police surrounded burning shacks. Some of the newly homeless huddled in the rubble with the few belongings they could salvage.

Officials with President Robert Mugabe's ruling ZANU-PF party dubbed the campaign Operation Restore Order, describing it as a city cleanup in the wake of recent elections, which were condemned by the international community as unfair. But others said it was retribution against the urban poor, who had voted overwhelmingly for the opposition Movement for Democratic Change.

"People were tired and confused," said Trudy Stevenson, an MDC official in north Harare. "They spent the entire night destroying their own houses at gunpoint.

"They were saying, 'What are we going to do?' A lot were saying, 'Now we see the government is cruel.' There were children standing among their belongings looking very confused."

The demolitions began Thursday evening, when more than 3,000 police were deployed to evict people from their shacks. Further operations are planned for the coming days. The displaced people were to be taken to a new location outside Harare, but many were spending their second night in the open Friday, with winter just weeks away.

MDC activist Tonderai Ndira, 28, from the Harare suburb of Mabvuku, said he saw dozens of people being beaten by police as they resisted the shack demolitions in the Kudzawana district.

The police "were burning the houses," Ndira said. "People were angry. They were retaliating and throwing stones at the police. They were denying to vacate their houses, so they were being forced."

But in other areas, witnesses reported that frightened residents had meekly destroyed their dwellings as ordered.

The demolitions follow last week's crackdown on Harare's thriving black market. Police surrounded street traders, burned or bulldozed their stalls, destroyed their goods and arrested thousands.

Zimbabwe's economic crisis and high levels of unemployment have forced many urban poor to become illegal traders. The crackdown comes amid severe shortages of food and gasoline across the country after the almost total failure of this year's harvest due to drought and controversial agricultural policies.

Stevenson, the MDC official, said the people evicted in the area of Hatcliffe Extension, part of her electorate, were legal occupants who had paid 300,000 Zimbabwean dollars for the right to occupy their plots as part of a joint project of the World Bank and the Zimbabwean government several years ago.

The current value of 300,000 Zimbabwean dollars is only about $33 at the official exchange rate, as galloping inflation has left the nation's currency worth less than a tenth of its value of two years ago.

"People are going to be in the open for a second night. They have no shelter. Their food is gone. It's cold here. This is cruelty in the extreme," Stevenson said. "It's retribution, in my view, because the city voted MDC and [the government] want to just finish us off."

She estimated the number of homeless in Hatcliffe Extension at 6,000 to 7,000.

Harare's Friday Herald newspaper reported that police Commissioner Augustine Chihuri had warned that his forces would deal decisively with anyone resisting Operation Restore Order.

Chihuri said the "greedy" traders and "vagrants" had almost turned the cities of Harare and Bulawayo into "filthy shack townships," the newspaper reported.

He added that the government had "stepped up efforts against belligerent and unscrupulous businesspeople whose misdirection and insatiable desire for corruption has permeated the entire economic fabric of our beloved nation."

John Robertson, an independent, Harare-based economist, said the crackdown on traders had removed the livelihoods of thousands of families and would leave them hungry.

"The government is attacking the symptoms of a much bigger problem, which is that the government has made such a mess of its investment policies that no one has a job. There's not much people can do other than buying and selling. When people are desperate, they become very inventive."

He said the government might be getting tough now to discourage uprisings should the food shortage worsen in the coming months. Authorities "may be fearful of a much bigger uprising later unless they demonstrate their forcefulness now," Robertson said.