Isolated native people likely to be fleeing attacks in Peru have turned up in Brazil’s Amazon rainforest where they made contact with the outside world, according to a video released by the country’s indigenous authority.

Brazilian experts have said the tribespeople probably crossed the border as they had come under pressure from illegal logging and drug trafficking at home.

The tribe, part of the Pano linguistic group, made contact with the Ashaninka native people of northern Brazil in late June.

The meeting was documented in a video that was released by Brazil’s National Indian Foundation (Funai). In one scene an Ashaninka Indian in shorts gives bananas to two naked tribespeople armed with bows and arrows on the banks of the Envira river in the Brazilian state of Acre on the border with Peru.

Funai said its own team’s encounter was filmed on the second day of contact on 30 June.

Jaminawa Jose Correia, an Ashaninka who spoke with the tribespeople, said they had come in search of weapons and allies.

“They described being attacked by non-native people and many died after coming down with the flu and diphtheria,” he said.

Funai said the group returned to the forest but came back three weeks ago because they had contracted the flu. A government medical team was sent to treat seven of them.

Rights group Survival International said the episode was extremely worrying, considering that influenza epidemics have wiped out entire tribes in the past.

The Brazilian Amazon has the largest number of uncontacted tribes in the world at 77, Funai estimates.