Three suspected illegal miners were killed in a shootout that erupted after they entered an indigenous area in the Brazilian Amazon.
The Yanomami group said armed miners on seven boats attacked a remote community on Monday. One indigenous person and four other miners were injured.
An estimated 20,000 illegal gold miners are in the Yanomami area, Brazil’s largest protected indigenous reserve.
Violence in the Amazon has increased under President Jair Bolsonaro.
The far-right president, a critic of the size of the indigenous reserves, has promised to open some of them to agriculture and mining. His government has weakened environmental protections, and critics say his rhetoric has emboldened illegal activity in the region.
Junior Hekurari Yanomami, from the Yanomami-Ye’kuanna group, said the half-hour shootout happened in the Palimiú community in Roraima state, near the border with Venezuela. About 930 people live in the area.
The miners gathered near the Uraricoera river, which is often used by illegal miners to transport petrol and other goods to their camp.
In a letter to federal authorities, Mr Hekurari Yanomami called for “urgent action to stop the spiral of violence in the area and to guarantee the security of the community”. He said members of the indigenous group were sheltering in the jungle as the miners had threatened to retaliate.
It was the third incident between indigenous people and illegal miners in the area in two weeks.
In March Instituto Socioambiental (ISA) said an area equivalent to 500 football pitches had been destroyed by mining in the Yanomami territory last year alone, with most of the activity located around the Uraricoera river.
Work by miners intensified after President Bolsonaro took office in 2019, the report said. Mining camps, once located in areas deep in the jungle, were getting closer to indigenous villages, it added, increasing the risk of conflict.
Rivers used by indigenous communities are being contaminated by mercury that is released from mining, while miners are also believed to have brought diseases to the area, including Covid-19 and malaria.
Activists and indigenous groups have denounced President Bolsonaro’s lack of action against illegal logging and mining in protected areas, and say environmental enforcement remains underfunded.
The president rejects the criticism, saying Brazil remains an example for conservation. But last year, deforestation in the Brazilian Amazon surged to a 12-year high.