Isolated tribe makes uncomfortable contact

Peruvian authorities are struggling to keep outsiders away from a clan of previously isolated Amazon Indians who began appearing on the banks of a jungle river popular with environmental tourists last year.

The behaviour of the small group of Mashco-Piro Indians has puzzled scientists, who say it may be related to the encroachment of loggers and by low-flying aircraft from nearby natural gas and oil exploration in the south-eastern region of the country.