A pair of stolen sandshoes has sparked a fierce tribal battle in Papua New Guinea's Western Highlands province that may have killed several people.
About 15 men, women and children, some as young as six, were seriously wounded in fighting between Eastern Highlanders and members of the Western Highlands' Moge tribe in Mount Hagen on Sunday.
The deputy police commissioner, Gari Baki, says it's not yet clear how many people died in the fighting, but a local doctor says it could be as many as four.
The doctor also says children were targetted and received deep knife wounds.
Police deputy commissioner Baki says reprisals have followed with Eastern Highlanders in Goroka, destroying a bus and damaging another owned by Western Highlanders from Mount Hagen.
He says it is known as payback.
"Yesterday, there a report of somebody being killed and a typical Highlands' mentality, you know, if somebody dies there has to be violence and you can only get satisfaction when somebody else gets injured or gets killed. And that's basically what has happened. That's in retaliation. It's called payback, so as a payback of the report that one of the Eastern Highlands people have got killed in Mount Hagen, they resort to violence yesterday in Goroka in damaging cars and buses, which belongs to the people of the Western Highlands."
Mr Baki says peace talks are under way between the groups, but the police are on a state of alert and the atmosphere in the city of 300,000 is tense.