At least one Indonesian soldier has been killed in a rebel attack while searching for a kidnapped New Zealand pilot in the Papua region, officials say.
Rebels later claimed nine soldiers were shot dead in the clash, while the Associated Press cited military sources that put the death toll at six.
The troops were part of a detachment sent to locate Philip Mehrtens, who was taken hostage in February.
Papua rebels have been seeking independence from Jakarta for decades.
The Indonesian troops were attacked on Sunday while searching for Mr Mehrtens near a separatist stronghold in the mountainous Nduga district, the military said.
Gunmen shot a soldier who fell into a 15m-deep ravine, then launched a second attack while troops were recovering the body, First Admiral Julius Widjojono told reporters.
“The condition of the other soldiers who are spread in several locations is still unknown,” he added.
The West Papua National Liberation Army (TPNPB) claimed responsibility for the attack, which it said was launched to deter military efforts to rescue Mr Mehrtens.
“The United Nations and the New Zealand government have an obligation to push Indonesia to stop the military operation,” rebel spokesman Sebby Sambom said in a statement.
The 37-year-old pilot was captured shortly after landing his single-engine plane in Nduga to drop off passengers.
A video of Mr Mehrtens surrounded by heavily armed men was later released by rebels, who have said they will release him if Papua is granted independence.
Independence-seeking rebels have previously issued threats and attacked aircraft which they believe are carrying personnel and supplies for Jakarta.
The region is divided into two provinces, Papua and West Papua. It is separate from independent Papua New Guinea.
Previously a Dutch colony, West Papua declared independence in 1961. However Indonesia took over two years later and was formally given control in a UN-supervised vote in 1969.
The UN vote is widely considered illegitimate as only about 1,000 Papuans took part in it. A pro-independence movement began shortly afterwards, which continues to this day.
Conflicts between indigenous Papuans and the Indonesian authorities are common, with separatist fighters increasing their attacks since 2018.