Two suicide bombers detonated themselves outside the church on the island of Sulawesi.
The police officials said that there were body parts at the scene, but they were yet to be identified.
The attacker arrived near the Church on a motorbike and was trying to enter the Church hall, according to local sources.
Wilhelmus Tulak, a priest at the Makassar cathedral, said that a parking attendant had been burned when he tried to stop an attacker.
There was no immediate claim of responsibility for the attack. (ILKHA)