Suspected Peruvian drug traffickers recently overran a base of the National Indian Foundation in a remote region of Brazil's Amazon, the foundation said Tuesday.
The base was "invaded and looted late July by Peruvian drug traffickers" who were armed and chased away members of an isolated tribe living in the area, said the statement from the foundation, which is known as Funai and oversees indigenous issues in Brazil.
Federal police officers and Funai staffers who returned to the outpost last week found at an abandoned camp site a backpack with an arrowhead belonging to the tribe.
A Funai statement said the outpost is located in an Ethno-Environmental Protected Area along the Envira River in the state of Acre, just 20 miles (32 kilometers) from the Brazil-Peru border.
Funai president Mario Meira was scheduled to arrive at the outpost on Tuesday accompanied by a Justice Ministry official and federal police agents, the statement said.
According to the statement, the arrowhead belongs to the indigenous group that made international headlines in 2008 when tribesmen were photographed firing arrows at an overflying plane.
"The arrow head is like an identity card of the isolated Indians," Carlos Travassos, of Funai's isolated Indians division, is quoted as saying in the statement. "We are more worried than ever. This situation could be one of the biggest blows to our work protecting isolated groups in the last decades. A catastrophe for our society. A genocide!"
According to the statement, police arrested suspected drug trafficker Joaquim Fadista, a Portuguese citizen operating out of Peru.
In March, Brazilian police had arrested Fadista in the same area and extradited him to Peru where he was wanted on drug trafficking charges, the statement said.
He was arrested again when he returned to the area looking for a backpack apparently filled with drugs, the statement said. Further details on Fadista were not immediately available.
Most of Brazil's indigenous people continue to live in the jungle and maintain their languages and traditions. Many have fought for decades to keep or regain their ancestral lands.