On Monday, members of another family blew themselves up at a police station in the city, wounding 10.
The girl was with two other adult attackers on a motorcycle and was thrown out of the moving vehicle but survived, police spokesman Frans Barung Mangera said. More than 40 people were injured across all three churches, including police, and 14 people including the family of six were killed.
JAKARTA, Indonesia - A wave of deadly bombings Sunday and Monday and evidence of more planned have shaken Indonesia just before the holy month of Ramadan, with entire families - including children - carrying out suicide attacks against Christian worshipers and the police.
Al-Azhar Al-Sharif condemned in the strongest terms the terrorist attacks that targeted three churches in Indonesia and left dozens dead and wounded, a Monday statement said. "We are angry", said an official, but he insisted that civilians cooperate with police proceedings.
The group also claimed responsibility for a hostage-taking ordeal last week by imprisoned Islamic militants at a detention center near Jakarta in which six officers were killed. "One of them was a little kid", national police chief Tito Karnavian said.
At another church across town, the couple's two sons, aged 17 and 15, rode an explosive-laden motor scooter into a crowd and set it off.
The Bali and Jakarta Police Offices have put both destinations on highest security alert following a series of bombings in Surabaya and neighbouring Sidoarjo on Sunday. All members of the family died in the attacks, which ISIS claimed responsibility for via its Amaq News Agency in what it called "a martyrdom operation". "The attacks yesterday are part of a pattern ... but (are among) the more sophisticated, and as it involved children, heinous".
The father has been identified as Dita Oepriarto, according to CNN; he was reported to be the head of a branch of jihadi group Jamaah Ansharut Daulah (JAD), which has connections to ISIS, AP reported.
The victim's mother said the family was "proud to have a martyr who gave his life to save hundreds of people attending Sunday Mass inside the church building".
Correction: The name of the father in the church suicide bombings has been updated following further information from police. Nearly 10% of the population is Christian.