Brazilian police and environmental protection agents were ambushed by illegal gold miners on the Yanomami Indigenous reservation in the Amazon on Monday and four miners were shot dead in the exchange of gunfire, a government statement said.
The Environment Ministry said their team was attacked when they moved in to dismantle a wildcat mining camp run by an organized crime gang.
Brazilian authorities are keen to show that they mean business in their efforts to remove the remainder of the wildcat miners on the reservation following the fatal shooting of a Yanomami man.
Gold miners killed one man and seriously injured two others in an attack on Saturday in the Yanomami territory, where authorities have been evicting illegal miners who invaded Brazil's largest indigenous reservation, the size of Portugal.
According to Minister of Indigenous People Sonia Guajajara, about 80% of the more than 20,000 gold miners that invaded the reservation have been evicted and those still there are resisting removal more violently.
Environment Minister Marina Silva said 300 mining camps had been dismantled, and 20 planes and one helicopter destroyed by agents of the environmental protection agency Ibama, that is continuing to seek the remaining miners with the help of police.
President Luiz Inacio Lula da Silva vowed when he took office in January to remove the miners, whose presence caused a humanitarian crisis, spreading disease and causing malnutrition among the Yanomami by reducing their game and poisoning rivers.
A large-scale enforcement operation was launched in February and most miners began to leave or were forced to go.
Lula has pledged zero tolerance for mining on indigenous land protected by the Constitution and the environmental protection agency is planning eviction operations on five other reservations where illegal logging and mining increased under previous President Jair Bolsonaro.
(Reporting by Anthony Boadle; Editing by Sandra Maler)