Authorities in Ecuador are probing claims that five Amazon tribespeople have been killed by illegal loggers.
The group, from the Taromenane and Tagaeri tribe, was attacked in the eastern Yasuni National Park - a protected area - reports say.
A tribal leader said they had tried to stop the loggers felling trees, and revised downwards an earlier estimate of up to 15 dead.
Correspondents say such clashes are common, with loggers search for trees.
Valuable trees, such as mahogany, are particularly sought after.
Police say they are unable to confirm the reports and do not have the means to reach the remote region, but a group of indigenous leaders are travelling to the area to investigate.
"It's difficult to know if there were only five murdered or more. To tell the truth, it is a dangerous trip," Enqueri Nihua Ehuenguime, president of the Huaorani Nationality Organization of Ecuador, told the Associated Press news agency.
Reports say the tribes people were killed and their heads cut off, BBC South America correspondent Daniel Schweimler says.
The Taromenane and Tagaeri are one of several groups native to the 700,000 hectare park, where logging is prohibited.
Many of the groups have little or no contact with modern society.
In recent years there have been reports of similar killings - sometimes the result of clashes with loggers, other times because of violence between rival tribes, our correspondent says.