Seven people have been injured and buildings and cars vandalised as Indonesian police and mine workers clashed near the Freeport McMoran gold and copper mine in Papua.
Indonesia's Antara News reports that the violence occurred as hundreds of local mine workers and residents were leaving a company event in Mimika district late Saturday afternoon.
A Freeport spokesperson says the cause of the violence remains unclear and the situation is under control.
However, Papua Police Chief Inspector General Tommy Jacobus is quoted as saying the crowd mistook an attempt by policemen to halt a fight between a couple of drunken locals as an attack on them.
Tension still runs high in the area following a five-day blockade by allegedly illegal miners barred by the company from prospecting for gold in the mine's tailings last month.
In March, a violent mass protest in the Papuan capital Jayapura demanding closure of the mine left six people dead.