Some 2,000 people living in a shanty town on the outskirts of São Paulo erected burning barricades to resist police attempts to evict them.
Smoke rose above the Capão Redondo slum in the south of Brazil`s biggest city as dozens of police officers moved in to dislodge residents.
They were trying to end a two-year illegal occupation of land.
One person was injured and two people arrested, a police spokesman said, adding the situation was under control.
As police officers moved in early on Monday, they were confronted by barricades of tyres and cars.
The fires spread to several of the wooden houses in the slum and were threatening others.
Police fired tear gas to disperse protesters who threw stones and Molotov cocktails, the AFP news agency reported.
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