Indonesian police have begun a manhunt in the Timika area of Papua province after two employees of the US mining giant Freeport were killed in separate attacks at the weekend.
A 29-year-old Australian was shot to death on Saturday while traveling in a car near the company's massive Grasberg copper and gold mine in the province.
On Sunday, gunmen opened fire on two Freeport vehicles, killing a local security guard, then ambushed anti-terrorist squads responding to the assault.
A third death related to the shootings has been confirmed, with the discovery of the body of a police officer from the unit which responded to the Sunday attack.
The US-based group, the West Papua Advocacy Team, says there are some key parallels between these shootings and those which killed three Freeport employees in Timika in 2002.
US and Indonesian investigators found that Papuan separatists were behind the 2002 attack but local rights groups have long maintained the military had a hand in the killings.
The group's Ed McWilliams says that based on police reports about the latest shooting, it was carried out on the same road from the mine as the 2002 attack which was also an ambush involving security forces weaponry.
Two Australian federal police have gone to Papua to assist in the investigation which Ed McWilliams says will need to be a lot more probing than the one which followed the 2002 attacks.
"The investigation could be a lot more thorough then what we saw in 2002, that it would involve perhaps international assets but also perhaps also bring in the Indonesian human rights commission, which would have a lot more credibility than a simple military investigation which is what happend in 2002."
Recently released documents from the US State Department show that as then Minister of Political and Security Affairs, Indonesia's current President Susilo Bambang Yudhoyono tried to stall FBI attempts to probe the 2002 attack.
