The Brazilian government has opened an investigation into the deaths of 10 members of an uncontacted indigenous tribe, allegedly at the hands of gold miners.
Authorities said the prosecutor's office in the Amazonas state, near the Colombian border, opened an investigation after learning that the miners had bragged about killing members of an unidentified tribe.
Brazil's National Indian Foundation said some of the prospectors have been detained for questioning, but they have not confirmed any deaths.
London-based activist organization Survival International says those killed were a part of Brazil's 103 uncontacted tribes, defined as having "no peaceful contact with anyone in the mainstream or dominant society."
Miners routinely encroach on tribal lands in Brazil, often ending in deadly encounters.