At least 24 construction workers have been killed by gunmen in Indonesia’s eastern province of Papua, officials said.
A soldier was also shot dead when a team of police and security forces were sent to investigate Sunday’s killings, authorities added.
The workers had been building a road and bridges in the remote and mountainous Nduga region.
Police have blamed the deaths on separatist fighters.
Insurgents calling for independence have been active in Papua for decades.
Military spokesman Colonel Muhammad Aidi said the incident started when members of an “armed criminal separatist group” held a ceremony to commemorate what they considered to be their independence day on 1 December.
Col Aidi said one of the workers from the construction company PT Istaka Karya was reported to have taken a photograph of the group, which angered them and triggered the attack.
The bodies of the workers were found near a bridge they were building, he said.
Police and troops who arrived in the area on Monday to investigate came under gunfire, leaving one soldier dead and another wounded, officials said.
Construction work in the dense jungle is part of President Joko Widodo’s infrastructure push, an attempt he says to bring development and prosperity to the resource-rich area.