Environmentalists in Brazil are mourning the death of a leading expert on uncontacted tribes in the Amazon, who was killed by an arrow that struck him in the chest.
Friends of Rieli Franciscato say he died inside the rainforest while on a mission to shield an isolated indigenous group from a possible hostile encounter with outsiders.
It happened on the edge of the Uru Eu Wau Wau reservation in the western Brazilian state of Rondônia, an area in which the forest has suffered heavily from invasions by illegal loggers and miners, and also from ranchers setting fires to clear land.
The killing prompted speculation that Franciscato was shot by the uncontacted group after being mistaken for an invader. His death, on Wednesday, was witnessed by a policeman, Paulo Ricardo Bressa, whom Franciscato had asked to accompany him on his expedition into the area.
Bressa says that Franciscato climbed a hill to see if he could verify whether isolated tribal people were moving through the area.
"We heard the noise of an arrow that hit his chest. He let out a cry, pulled out the arrow, and came running back. He managed to run 50 to 60 meters and then he collapsed, lifeless," said Bressa, in an audio message posted by Brazilian media.
Franciscato, 56, spent his career working for the Brazilian government's indigenous affairs agency, Funai, and earned a reputation as a tireless defender of isolated indigenous groups and their forest lands.
Survival International, an organization that campaigns for tribal peoples' rights, described his death as a "tragic and immeasurable loss."
"He refused to accept the violent greed destroying the Amazon rainforest and its best guardians," it said, "He worked tirelessly to protect the lands of uncontacted tribes from outsiders.
"He dedicated his life to it, working on the front line to combat the illegal invasions by loggers, ranchers and miners who threaten to wipe out the most vulnerable peoples on the planet."
Franciscato's death is reinforcing concern among forest protectors about the policies pursued by Brazil's president Jair Bolsonaro, who advocates the integration of the indigenous into broader Brazilian society and wants to exploit the Amazon's natural resources.
They accuse Bolsonaro of fueling violence in the Amazon region by cutting back government environmental protection agencies, and emboldening groups intent on invading indigenous lands. As evidence, environmental activists point to the number of fires now burning within the Brazilian Amazon. In the first nine days of this month, satellites used by Brazil's National Institute for Space Research detected 12,412 fires — more than double the number during the same period last year. Many of these are set by illegal ranchers clearing already deforested land.