A group of illegal gold miners were reportedly overheard boasting about killing as many as 10 members of a reclusive, uncontacted Amazonian tribe in Brazil last month. The attack, which potentially wiped out one-fifth of the tribe, is believed to have included women and children.

According to the Washington Post, an unidentified person overheard the miners reliving the massacre at a bar. After hearing disturbing details, the person began recording the miners' conversation and turned the audio over to authorities. Carla de Lello Lorenzi, communications officer for indigenous rights organization Survival International, said the tribe members were greater in number, but the gold miners, likely equipped with more weaponry, overpowered the tribe and killed them all. Lorenzi also said the miners cut the tribe members' bodies "so that they wouldn’t float," then dropped them in a nearby river. As if that wasn't sick enough, the attackers also collected tools and jewelry from the indigenous dead as a way of commemorating the occasion.

Authorities have since launched an investigation into the reported killings, and two suspects have been arrested. 

FUNAI, Brazil's indigenous affairs agency, was recently impacted by budget cuts under Brazilian President Michel Temer. Survival International Director Stephen Corry says the attack was genocidal, and placed blame for the incident squarely on Temer's government. "The slashing of FUNAI's funds has left dozens of uncontacted tribes defenseless against thousands of invaders—goldminers, ranchers and loggers—who are desperate to steal and ransack their lands," Corry said. "All these tribes should have had their lands properly recognized and protected years ago—the government’s open support for those who want to open up indigenous territories is utterly shameful, and is setting indigenous rights in Brazil back decades."

Survival International has released some of the only known footage of Brazil's isolated Amazonian tribes, which can be viewed at the top of this page.