Five members of an indigenous Amazonian tribe have been arrested on suspicion of murdering three contractors who have not been since mid-December.
The Tenharim tribe members are accused by local groups of killing the three men in retaliation for the death of a tribal leader.
Ivan Tenharim was run over by a car in the tribe's reserve in early December.
Tribal leaders said he was killed deliberately, but the police argue that the death was an accident.
For decades, indigenous tribesmen and locals have clashed over the Tehranim practice of setting up road blocks and asking for payment from people wishing to travel through their land as compensation for it being stolen from them.
The three contractors were last seen on 16 December, trying to cross the Transamazonica highway on Tenharim land.
The bodies of the men, named as teacher Steff Pinheiro de Souza, Aldeney Ribeiro Salvador, who worked for the state utility company Electrobras and businessman Luciano Ferreira Freire, have not been discovered, with police apparently believing that their bodies were dumped in a river.
After their disappearance, thousands of townspeople from Mumaita descended on the reserve, torched cars, and attacked buildings belonging to the National Indian Foundation; hundreds of Tehranim sought refuge in nearby military barracks, and only returned days later.
Hundreds of police were deployed on the remote reserve, which is 370 miles from state capital Manaus, and two days after Christmas began the unsuccessful search for the missing men.
The suspects were arrested on the reserve on Saturday morning.