Jakarta – Nineteen people are still on the run following last month's riots in Indonesia's Papua province in which six people were killed, police said.

Four of the fugitives described as the "main actors" are suspected of being responsible for the deaths of five security officers in the March 16 riot at a US-run mine, Papua chief detective Paulus Waterpauw said.

"They are the coordinators of the rally and the individuals chiefly responsible for the death of our men. We believe they are still hiding in Papua," he told AFP by telephone.

Hundreds of protestors demanding the closure of a gold mine operated by a subsidiary of US mining giant Freeport-McMoRan clashed with security forces. Four paramilitary policemen, a navy officer and a civilian were killed.

A total of 20 suspects were currently in detention and prosecutors had completed court dossiers for eight of them, said Waterpauw. Those held face various charges, including inciting enmity against the government in public, violence causing death or injury and illegal possession of crude weapons.

The clash followed weeks of protests over the world's largest gold and copper mine, which is one of the Indonesian government's top sources of revenue.

Critics accuse Freeport-McMoRan of not giving enough to the people of Papua in return for the mine, which critics say causes pollution and is responsible for human rights abuses because of the military's protection of the site.

The latest violence has fanned fears of further unrest in the isolated province, some 3,000 kilometres (1,800 miles) from Jakarta, where Indonesia has grappled with a sporadic separatist conflict for decades.