SYDNEY, Australia  —  Police in rural Papua New Guinea said Friday they were investigating the killing of a woman who was tied to a wooden pole, surrounded by rubber tires and set on fire.

A group of people bound and gagged the young woman, carried her to a rubbish dump and lashed her to the pole before setting her alight on Tuesday, said Simon Kauba, assistant commissioner of police and commander of the remote and rugged Highlands region, where the slaying occurred.

Rumors that the woman was killed because she was suspected of witchcraft have spread through the South Pacific island nation, but Kauba said that was just one of many theories police were investigating as a motive behind the woman's death.

"We do not know the motive behind what happened," Kauba said. "At this point in time, we have some good leads and we're working on them."

Police are still trying to determine the woman's identity.

In rural Papua New Guinea, witchcraft is often blamed for unexplained misfortunes. In 2007, two men in the country's Milne Bay province were sentenced to death by hanging after beheading a woman they believed had killed their fathers with a spell.