Among those arrested were loggers, highway and military police officers, neighbouring farmers and state civil servants.

The loggers bribed officials of the government's Indian foundation Funai and befriended Indians with gifts such as cars, motorcycles and chain saws, a police spokeswoman told Reuters from Mato Grosso.

The arrest follows rising concern over the rain forest among environmental groups after Environment Minister Marina Silva, who was seen as a guardian of the Amazon, stepped down on May 13.

They fear the government of President Luiz Inacio Lula da Silva is accelerating big infrastructure projects such as roads and hydroelectric plants that will destroy more forest.

Country-sized chunks of the Amazon forest are cut down every year. Conservationists blame farmers and cattle ranchers for pushing deeper into the forest in search of cheap land to boost output as commodity prices soar.

Defence Minister Nelson Jobim announced earlier this month that the army would deploy troops in Indian reserves along the country's borders. The military and conservative politicians expressed concern the unprotected reserves made Brazil's borders vulnerable to drug traffickers and Colombian guerrilla fighters.