A woman has been beheaded in Papua New Guinea after being accused of practising sorcery, reports say.
Police said they tried to intervene during the woman's killing in South Bougainville last week, but were met with an angry mob.
The woman was accused of practising sorcery that caused the death of a teacher in Lopele village, they added.
In parts of the Pacific nation deaths and mysterious illnesses are sometimes blamed on suspected sorcerers.
Several reports have emerged in recent years of accused people, usually women, being killed.
Papua New Guinea's Post-Courier newspaper reports that two women were killed on Thursday evening. But other reports say only one woman died.
"We were helpless. We could not do anything," police inspector Herman Birengka was quoted by the newspaper as saying.
Police said villagers armed with weapons outnumbered police and looted property. They have identified suspects, but arrests have yet to be made.
Hundreds took to the streets in Bougainville on Monday to protest against the beheading, rights group Human Rights Watch told Radio Australia.
Last month, a 20-year-old woman was burned alive after she was accused of sorcery. The case has drawn public condemnation, with officials calling the act "barbaric".
In 2009, after a string of such killings, the chairman of Papua New Guinea's Constitutional Review and Law Reform Commission said defendants were using accusations of witchcraft as an excuse to kill people, and called for tougher legislation to tackle the issue.