Church engulfed in fire
“There is one location where we can’t enter yet,” Mr Mangera said.
Television footage showed one church engulfed in fire, with thick, black smoke billowing up.
A large blast was heard hours after the attacks, which Mr Mangera said was a bomb disposal squad “securing” a remaining device.
Inspector general Machfud Arifin told CNN Indonesia that one of the suicide attacks was carried out using a motorbike, another using a car.
Two police officers were among the injured.
The toll could rise further, police warned.
El Shinta radio station says the almost-simultaneous attacks occurred during Sunday morning Masses.
Authorities were also investigating whether there was an explosion at a fourth church.