The crash was not because of a terrorist attack, the governor said, here, Sunday evening.
The helicopter crashed when trying to land at Kasiguncu airport, Poso District, Central Sulawesi, amid an extreme weather, he added.
Commander of the Tadulako Military Regiment 132 Colonel Saiful Anwar, who led a manhunt operation for alleged terrorist Santoso, was killed together with 12 other officers in the accident.
The jungles in Poso mountainous areas are known to be the hiding places of long sought Santoso and his men.
From early 2015 until January 9, 2016, joint police and military forces had launched security operations dubbed Seagull Maleo I to IV involving thousands of personnel, as well as warships and jet fighters in Poso.
During the Seagull Maleo IV operation, the forces managed to arrest 17 alleged terrorists and killed seven others, but Santoso was not among them.
Following the conclusion of the Seagull Maleo operations, the authorities have launched another security operation termed Tinombala to continue their hunt for Santoso and his men in the jungles of Poso, Central Sulawesi Province, since January 10, 2016, for two months.
At least three alleged terrorists, comprising two Chinese Uighur, and one Indonesian, were shot dead in Poso earlier this week.(*)