Police in Indonesia's West Papua province on Tuesday said at least 19 people died as two rival gangs fought, sparking a fire.

Officials said members of two ethnic groups attacked one another. Police said the clash in Sorong city did not involve locals from remote West Papua, where there is a long-running, low-level insurgency.

What happened at the club?

Police said the fight was part of a prolonged dispute that had started on Saturday evening and had resulted from a misunderstanding. 

"We tried to mediate between the groups, as we called their leaders before last night's clash," Sorong police chief Ary Nyoto Setiawan said in a statement.

All the bodies in the "Double O" nightclub were found on the second floor of the building. One of the victims had been stabbed and the 18 other fatalities had died in the fire.

Setiawan said a team was investigating the cause of the blaze, which gutted the building. A burnt-out vehicle lay on its side by the blackened entrance to the club in the aftermath. 

As well as attacking one another with machetes and arrows, some of those involved in the fighting had used Molotov cocktails.

Police said they had deployed forces in Sorong to prevent any further clashes.

Separate communities with few links

The Papuan Melanesian population, which is mostly Christian, shares few connections with those living in the province from the rest of Indonesia who are mostly Muslim.

Sorong, which is the largest city in West Papua province and home to a major port, is relatively quiet compared to other regions of West Papua. The other areas of the region have seen fighting amid an ongoing insurgency between separatists and Indonesian security forces.

That fighting has recently escalated with attacks on road contractors, as well as schools and clinics that the insurgents say have links to the military. Authorities have deployed troops and police there in response.

The mineral-rich province on the island of New Guinea, just north of Australia, shares a border with independent Papua New Guinea.

A former Dutch colony, it declared independence in 1961 but was taken over by neighboring Indonesia two years later. Jakarta promised an independence referendum but the subsequent vote in favor of remaining part of Indonesia is widely considered to have been fixed.

rc/rs (dpa, AFP, AP)