Human-animal conflicts are rampant in the vast Southeast Asian archipelago, especially in areas where the clearing of rainforest to make way for palm oil plantations is destroying animals' habitats and bringing them into closer contact with people.
Locals from Hatupangan village in North Sumatra had initially suspected the tiger was a supernatural creature so they followed it to its jungle lair, the official said.
The tiger -- which has been seen around the village since last month -- attacked the curious group Sunday, leaving two villagers seriously injured.
"Unfortunately they would not listen. They insisted on killing the tiger," local conservation agency head Hotmauli Sianturi told AFP, adding that a conservation officer was blocked from preventing the death.
More From This Section
"After killing the animal, the locals hung up its body for display. It's very regrettable."
Some internal organs were missing from the tiger's body, said authorities, who are investigating the killing.
Sumatran tigers are considered critically endangered by protection group the International Union for Conservation of Nature, with 400 to 500 remaining in the wild.