Officials in Brazil have said they had no news of an isolated tribe of Amazonian natives who may have been attacked by suspected Peruvian drug traffickers, amid fears of a bloodbath.
Employees of Brazil's National Indian Foundation (FUNAI) have been searching for signs of the natives following an attack in late July on the remote Xinane guard post tasked with protecting the tribesmen near the Brazil-Peru border.
"The five employees have still not seen the natives. They fear there was a slaughter but nothing has been confirmed," a FUNAI spokeswoman in Brasilia told AFP.
"The armed men who attacked the guard post are still in the vicinity, as FUNAI employees have seen fresh footprints."
In January, Brazil allowed the release of rare photographs of the natives -- astonishing images taken by FUNAI showing adults and children peering skyward with their faces dyed reddish-orange and toting bows, arrows and spears.
FUNAI says there are dozens of tribes in Brazil that do not have sustained contact with the outside world. Some are often referred to as "uncontacted" tribes. Only 30 of them have been identified.
The Brazilian government prohibits unmonitored outside contact with these groups, as outsiders could be infected with potentially fatal illnesses to which the natives have never been exposed.
In March, Brazilian police arrested a Portuguese trafficker believed to be the leader of the armed group that attacked the Xinane outpost and extradited him to Peru, FUNAI said.
He was arrested again on Friday for "aggravated theft and clandestine smuggling of a foreigner expelled from Brazil," said a spokesperson for police in Acre's state capital Rio Branco.
On Saturday, FUNAI employees discovered the backpack of one of the suspected Peruvian traffickers, which contained a broken arrow and 20 kilograms (45 pounds) of cocaine near the guard post in Acre.
FUNAI president Marcio Meira traveled to Rio Branco, the capital of Acre state, with Public Security Minister Regina Miki to meet the state's governor and discuss the situation.
According to the Estado de Sao Paulo newspaper, Meira wants the defense ministry to step up efforts to protect the border with Peru -- the region with the most "uncontacted" tribes.
Stephen Corry, the director of tribal rights group Survival International, lamented what he called the "extremely distressing news" about the missing natives.
"There is no knowing how many tribal peoples the drugs trade has wiped out in the past, but all possible measures should be taken to stop it happening again," he said.
"The world's attention should be on these uncontacted Indians, just as it was at the beginning of this year when they were first captured on film."
Explore further: Researchers outline recommendations to improve scientific decision-making