Uncontacted tribes photographed in remote region of Brazil

(CNN) - Dramatic photographs have emerged of one of the few remaining peoples on earth who are thought to have had no contact with the outside world. Taken from a small airplane, the photos show men outside thatched communal huts, necks craned upward, pointing bows toward the air in a remote corner of the Amazonian rainforest.

The National Indian Foundation, a government agency in Brazil, published the photos Thursday on its Web site. It tracks "uncontacted tribes" - indigenous groups that are thought to have had no contact with outsiders - and seeks to protect them from encroachment.

More than 100 uncontacted tribes remain worldwide, and about half live in the remote reaches of the Amazonian rainforest in Peru or Brazil, near the recently photographed tribe, according to Survival International, a nonprofit group that advocates for the rights of indigenous people.