Eight Papuan men have been arrested over a deadly ambush on a security convoy near the giant Freeport gold and copper mine in Indonesia's Papua province, police said on Tuesday.
The detainees included the alleged gunman who opened fire on the convoy on July 12, killing a Freeport security guard, police said. A policeman who escaped the ambush was found dead in a ravine the following day.
"We arrested eight people... one carried out the shooting and the other carried ammunition," provincial police chief Bagus Ekodanto said.
"We are still investigating the other six."
Ekodanto refused to name the suspects or say whether they belonged to the separatist Free Papua Movement.
The attack was one of several military-style ambushes on Freeport and police vehicles on the road between Timika town and the Grasberg mine which killed three people earlier this month.
A day earlier gunmen had ambushed a Freeport vehicle on the same road, killing an Australian project manager at Grasberg, which is owned by the local subsidiary of US company Freeport McMoRan.
Ekodanto said police were not "yet" linking the two attacks on July 11 and 12, although they took place within a short distance from each other on the same road leading to the mine.
Military chief General Djoko Santoso has blamed separatist rebels for all of the attacks, but police have said there is no indication that is the case.
Senior officials have said ex-soldiers or police could have been involved as part of a dispute over control of access to lucrative illegal mining operations using tailings from Grasberg.
Defence Minister Juwono Sudarsono has even suggested the involvement of foreign countries that have an "interest in destabilising Freeport".
The Grasberg mine sits on the world's largest gold and copper reserves and is a lightning rod for discontent over rule from Jakarta, which took control of the eastern Papua region in 1969 in a UN-backed vote widely seen as rigged.
Papua is the scene of a long-running separatist insurgency by poorly armed local guerrillas who have reportedly denied killing the Australian.
Indonesia refuses to allow journalists and foreign aid agencies free access to the resource-rich area, citing fears they will "agitate" over issues such as human rights abuses by the Indonesian military.