"He dropped his wife and two daughters, FS, 12, and VR, 9, at GKI", Karnavian said, referring to one of the three targeted churches.
The following attacks were timed five minutes apart with the father driving a vehicle filled with explosives onto the grounds of the Surabaya Centre Pentecostal Church. "Both blew themselves up in front of the church". Gen. Idham Azis said in a circular distributed to police stations in the capital.
While there's been a rise in the number of women being recruited to these kinds of terrorist cells, this marks the first time children have been involved in an attack in Indonesia.
The bombings at three churches in Surabaya were Indonesia's deadliest for years, as the world's biggest Muslim-majority country grapples with homegrown militancy and rising intolerance towards religious minorities.
The mother and the daughters, who had bombs strapped to them, attacked the Diponegoro Indonesian Christian Church.
Smoke billows from burnt motorcycles following the suicide attack at the Pentacostal church in Surabaya, Indonesia, on Sunday.More news: Mercedes' Lewis Hamiton tops second practice at Barcelona
No report was immediately available on other casualties, injuries or damages. "Looking at the pieces, I realized that this is a bombing", he said. According to a security officer at the church, he was walking behind and trying to stop them, however the two women split up before detonating their explosives.
Mulyo tried to help the security officer but stopped after he saw a backpack on one of the children. A bomb squad conducted a controlled explosion of the devices, he said.
In 2016, ISIS claimed responsibility for a suicide bombing near a Starbucks in Jakarta that left two people dead and 24 wounded.
The US Embassy in Jakarta condemned the assaults. He said two police officers were among a total of 41 wounded. On the household's residence, investigators discovered three plastic packing containers containing pipe bombs, Surabaya police Grand Commissioner Rudi Setiawan stated.
One suicide bomber appeared to have been disguised as a churchgoer.
Indonesian President Joko Widodo is expected to visit survivors of the attack in Surabaya on Sunday. The director of State intelligence agency, Wawan Hadi Purwanto, has stated that this Sunday's attacks are likely to be related to this incident. "We suspect that there's a command from Nusakambangan for them to act", he added, referring to the name of a prison that houses some of Indonesia's most unsafe inmates.More news: Celtics open East finals by ripping Cavaliers
He added that terrorism was a crime against humanity that had nothing to do with any religion.
"We are angry", association official Gormar Gultom said, but urged people to let the police investigation take its course.
Jemaah Islamiyah, the network responsible for the Bali attacks, was obliterated by a sustained crackdown on militants by Indonesia's counterterrorism police with USA and Australian support.
National police spokesman Setyo Wasisto announced that police fatally shot four suspected militants and arrested two others early Sunday in West Java towns.
Police have closed all three areas as they examine.
JAD was blamed for the prison riot earlier this week.More news: Iran would remain part of deal: Rouhani
Christians, many of whom from the ethnic Chinese minority, make up about 9% of Indonesia's 260 million people.