And in the morning of Monday, May 14, a family of five on motorcycles detonated themselves at the checkpoint gate of Surabaya Police Headquarters, killing them and leaving four officers and six civilians in critical condition.
A family was also responsible for a series of suicide bombings on churches on Sunday, which claimed 13 lives.
As noted by the BBC, "The archipelago, home to 260 million people, has seen a resurgence of Islamist militancy in recent years but the scale of the attacks in Surabaya has raised fresh concerns about the potency of jihadist networks".
Karnavian said Futrianto drove a bomb-laden vehicle into the city's Pentecostal church.
The IS statement claiming responsibility for the attacks didn't mention anything about families or children taking part and said there were only three attackers.
Police chief Tito Karnavian told journalists at a press conference that family was among 500 people recently deported from Syria after they attempted to join IS but were arrested by Turkish police.
Karnavian identified the father as Dita Futrianto and said he was head of the Surabaya cell of Jemaah Anshorut Daulah, an Indonesian militant network affiliated with IS that has been implicated in attacks in Indonesia in the past year. "We believe she was thrown three metres or so up into the air by the impact of the explosion and then fell to the ground", said East Java police spokesman Frans Barung Mangera, adding she had been rushed to hospital.
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". CCTV footage shows her stumbling around after the blast. Police killed the men after they had produced weapons during the raid and evidence confiscated included revolvers, bullets and an arrow with a bomb placed on the end of it, Wasisto said.
Indonesia's president Joko Widodo condemned their action as "barbaric".
There were at least two other attempts to bomb more churches, but these explosives failed to detonate according to the Jakarta Post.
Christians are a minority group in Muslim-majority Indonesia.
By Christopher WellsPope Francis assured the "dear people of Indonesia", and especially Christians in the city of Surabya, that he was "particularly close" to them in the wake of deadly attacks earlier on Sunday.