Members of one of the most isolated tribes on Earth have briefly emerged from the Peruvian jungle to ask for food, according to local activists.
A group from the Mashco-Piro tribe made contact with villagers, apparently sparking a tense stand-off.
The tribe, which numbers in the hundreds, has had virtually no contact with the wider world.
Campaigners say logging and urban development have diminished the area in which the tribe can live.
The Mashco-Piro are one of several tribes designated by the government as "uncontacted people".
The government forbids direct contact because the tribes' immune systems are not thought able to cope with the type of germs carried by other Peruvians.
Anthropologist Beatriz Huertas told the Associated Press news agency that the tribe could sometimes be seen migrating through the jungle during the dry season.
But it was strange to see them so close to the village across the river, she said.
"It could be they are upset by problems of others taking advantage of resources in their territories and for that reason were demanding objects and food of the population," she said.
Footage filmed late in June and released by local rainforest campaign group AIDESEP and the Fenamad federation for indigenous rights showed the tribe members crossing the river.
Saul Puerta Pena, director of AIDESEP, said the footage showed the tribe asking for bananas.
"There is a canoe sent by another remote indigenous community, which does not live in isolation, to send them food," he said.
"But the tribe cannot come into contact with the remote community still because any illness could kill them."
There are thought to be between 12,000 and 15,000 people from "uncontacted" tribes living in the jungles east of the Andes.