Indonesian security forces in West Papua launched an offensive last week against the West Papua Liberation Army (TPNPB) command holding New Zealand pilot Philip Mehrtens hostage, RNZ Pacific can confirm.
The operation was launched at 1am local time on Thursday March 23 in Nduga, Highland Papua and triggered a retaliatory attack from the separatist group with several casualties now confirmed by both sides.
The TPNPB issued a statement on Sunday confirming the attack and said the operation violated the New Zealand Government's request for no violence.
The rebel group said their district commander in Nduga Egianus Kogoya, who led the capture of Mertens, was among those attacked by Indonesian forces.
They said one of their members was killed during the attack, but also claimed they have shot four Indonesian security personnel, killing one soldier and one police officer.
It is not clear at this stage if Mehrtens - who has been held captive for the last 50 days - was present in the jungle hideout which was targeted.
Some details of the joint statement from the political and militant wing of the West Papua Freedom movement about the attack have been corroborated by Human Rights Watch Indonesia.
"I have verified that statement by checking what the Indonesian police and also Indonesian Papua have reported," Andreas Harsono told RNZ Pacific.
Speaking from Jakarta, the human rights watch researcher said there has been a series of clashes between Indonesian security forces and Indigenous Papuan militant groups.
He said the conflict has been ongoing in the central and highlands Papua region over the past week.
"It is confirmed that it began with the attack against a West Papua National Liberation Army's so called headquarters I guess this is a jungle hideout on Thursday, March 23 1am," Andreas Harsono said.
RNZ Pacific has contacted New Zealand Ministry of Foreign Affairs for comment.
We have been told that they are working on a response.