The Indonesian military says three bombs were found under a bridge near the Freeport copper and gold mine in Papua province.
The Papua Military Commander Major General Mahidin Simbolon says the bombs were found on Saturday near Tembagapura.
He says one detonator exploded but failed to ignite its load while two other bundles of explosives were found nearby.
The commander says all the materials used for the bombs were believed to have come from the Freeport mining operations.