Thousands of Brazilian peasants waving red flags and machetes staged land invasions and roadblocks to speed agrarian reform, a leftist organisation backing the peasants said.

Agriculture Minister Roberto Rodrigues said farmers here – the world's top producer of sugar, oranges and coffee and a leading cattle nation – feared for their property rights.

"We can't stand by and just accept our farmers' lives are being made hell," Rodrigues told reporters, urging calm from all sides.

Over 10,000 families in Brazil's radical Landless Workers Movement, or MST, have streamed onto at least 34 ranches in recent weeks to demand that land they claim is unused or public property be given to the poor and unemployed.

"We don't have work in the countryside and we want agrarian reform because it's the cheapest way to create jobs and dignity," Gilmar Mauro, a national MST leader, told reporters.

The MST said that in the poor northeastern state of Pernambuco, the site of 20 invasions, more than 1,000 rural workers had blockaded a road and set hundreds of tires alight.

It said some 2,000 MST families had chopped down acres of eucalyptus trees on a ranch in northeastern Bahia to build homes and begin planting beans and maize.

The 20-year-old MST, inspired by the Mexican and Cuban revolutions, has vowed to cover Brazil's countryside with its red flags in a "Red April" meant to speed up the government's purchase and redistribution of unused farmland.