Police in the Western Highlands province of Papua New Guinea say nine people have died after a group of tribal men raided a coffee plantation.
The commander of the police station at Banz, near Kimil plantation, says nine people are dead.
Reports say a group of tribal landowners attacked the office of the local plantation manager on Sunday evening.
The Post Courier newspaper reports two men and three women from Wabag drowned in a river as they tried to flee, while two other men died after being attacked with knives.
A correspondent for the Post Courier newspaper in the provincial capital, Mount Hagen, says the situation is tense and the number of dead may be higher.
The deputy governor of the Western Highlands, Wai Rapa, says Australian police should be sent to the province to restore law and order.
"Australian police are urgently needed to secure law and order problems in Papua New Guinea I think. There's a big breakdown in law and order, we cannot really address the law and order."