One report, in Spanish newspaper El Pais, claimed that the soldiers demanded gold from the locals in exchange for internet access.

In the ensuing fracas, four people were shot dead and five others were injured.

According to local reports, one 45-year-old woman was killed alongside two 22-year-old men and a 30-year-old man. A 16-year-old boy was injured.

In the aftermath, it was reported that the tribespeople blocked attempts to fly injured soldiers out of the area, so a surgeon was dispatched to treat them at the scene.

An investigation has been launched, but such is the animosity towards outsiders, it is feared that post-mortems may be impossible to perform.

Confirming the incident, Amazonas state governor Miguel Rodriguez said on Facebook: “There was a confrontation between Yanomami brothers and companions from the Aviation component stationed in Parima B, after the Internet was not shared with them, generating a confrontational situation, which resulted in four deaths and five injuries.”

A video reportedly taken afterwards showed a group confronting a man believed to be a prominent general.

“You guys are supposed to come take care of us. They didn’t have to use weapons like that,” says a woman while in the background, crying can be heard. 

In the recording, the uniformed men promise that they will send someone of higher rank to negotiate with them. “Our laws say that any problem that occurs on the land of the Yanomami people is resolved on that land,” the indigenous woman replies.

The Yanomami first came into sustained contact with outsiders in the 1940s when the Brazilian government sent teams to delimit the frontier with Venezuela, according to Survival International – an organisation which champions tribal rights.

Soon the government’s Indian Protection Service and religious missionary groups established themselves in the area, bringing measles and flu which killed a number of tribespeople.

Since then, the area has been blighted first by an influx of 40,000 legal gold miners in the 1980s, and then by illegal miners after the practice was outlawed in 1992. The following year, 16 people were murdered by miners, some of who were convicted of genocide.

After this incident, officials and prosecutors have been sent to the area to try and ascertain exactly what happened and who is responsible.