"Those tribes are so remote that whatever happens up there (in Gimi) doesn't come out," Diana Panta of the University of Goroka told The Times.

"They could be doing anything to each other and noone would ever know."

The massacre of baby boys would be devastating for the tribes involved, she said. "If they kill the baby boys they are killing the tribe," she said.

Maybe they feel the tribes will die if they don't do something to bring the men to their senses.