The tribe that appears to have killed American John Allen Chau on remote North Sentinel Island in the Bay of Bengal is one of a number of vanishing peoples sealed off from the rest of the world.
The Sentinelese, as they’re known, are protected by Indian law to preserve their way of life and protect them from modern illnesses to which they have no immunity.
Laws banning outsiders from going within five nautical miles of the island are also there to protect strangers because the tribe, which has lived on the island for tens of thousands of years, has a history of forcefully repelling outsiders.