Teguh Muji Angkasa, a senior military officer in Papua, told a televised news briefing the military and police would conduct a joint investigation.
"We have been given the order to investigate the incident," said Teguh, "and if from the results of the investigation, soldiers were involved, they will be sternly sanctioned."
Six officers have been named as suspects, Lieutenant General Chandra W. Sukotjo told Reuters, after body parts were found in a river near the city of Timika. The military is investigating the murder of four victims, he said.
The victims had been looking to buy weapons from the military officers on August 22 before the deal went awry, he said.
Media reported the victims' bodies had allegedly also been mutilated, but Chandra declined to comment on the allegations.
Indonesia maintains a heavy military presence in Papua, where small groups of separatist fighters have for decades waged a low-level, but increasingly deadly battle for independence. The military has faced accusations of human rights abuses in Papua, which it has denied, but investigations into such allegations are rare.
Sebby Sambom, spokesperson for the West Papua National Liberation Army (TPNPB), called on the government to hold the perpetrators accountable or risk further violence.
"If Indonesian President Joko Widodo does not immediately take responsibility, then the TPNPB together with the Papuan people will take revenge in the same way," Sambom said in a statement on Monday.
Armed conflict in Papua has escalated significantly since 2018, with attacks by the TPNPB becoming deadlier and more frequent, with an increasingly high number of casualties on both sides, a report by the Jakarta-based Institute for Policy Analysis of Conflict (IPAC) noted in July.
The increased frequency of attacks was due to the TPNPB acquiring more weapons by raiding and stealing from a growing number of army posts, cross-border purchases and the illegal sale of government weapons by rogue officers, IPAC said.Â
