Angola has been criticised for evicting thousands of people from poor districts of the capital over the last four years and leaving them virtually destitute.
More than 3,000 homes have been destroyed in Luanda
Human Rights Watch (HRW) says some 20,000 vulnerable people have been affected in often violent evictions.
In most cases, the land is not formally expropriated or inhabitants given a chance to make claims, the group says.
The authorities say they either need the land for development projects or that the inhabitants were trespassing.
The New York-based human rights group says the problem dates back to the end of the Angolan civil war in 2002.
"Millions of Angolans were displaced during the civil war, but since then the government has forcibly evicted thousands more from their homes in the capital," said Peter Takirambude, HRW's Africa director.
"The government's post-war policies have resulted in the destruction of thousands of homes and repeated violations of human rights."
In its new report - They Pushed Down the Houses: Forced Evictions and Insecurity of Tenure for Luanda's Urban Poor - HRW says Luanda's estimated 4m residents hold no formal deeds or titles to their houses or land.
Luiz Araujo, director of SOS Habitat, an Angolan non-governmental organisation which co-wrote the HRW report, said many people had lived in the targeted areas for decades.
"Others settled according to custom, with the permission of elders," he said.
A 35-year-old woman described how the bulldozers arrived without any announcement.
"There was time for nothing... we couldn't take anything out. They broke my bed, my oven; they ran over everything.
"I was trying to get my stuff out and they threw me in the police car."
Another evictee, 22, from the same neighbourhood - Cambamba II - said he ran to get his wife and child out of the house before the authorities demolished it.
"We left holding each other, and they came to beat us with batons. We continued to hold each other, and they continued to beat us, pushed us and threw us to the ground," he told HRW.
"At the end, there were eight policemen hitting me and my wife, holding our one-year-old baby. Then they threw me into the police car."
HRW called on Angola's government to probe the allegations of excessive use of force by police and government officials.
It also said alternative accommodation and compensation should be provided for those affected.