Surabaya: Members of one family were behind a wave of blasts targeting three churches in Indonesia’s second city of Surabaya, police say.
At least 13 people were killed and dozens wounded in the attacks on May 13.
A mother blew herself and two children up at one church, while the father and two sons targeted two others, police chief Tito Karnavian told media persons.
Sunday’s bombings, which the Islamic State group has claimed, are the deadliest in Indonesia since 2005.
The national police chief, Tito Karnavian, said the attacks, which also killed six bombers and injured more than 40 others, were carried out by children, teens and adults from a family. They were among 500 Islamic State sympathizers who had returned from Syria.
Earlier in the day, Wawan Purwanto, of Indonesia’s intelligence agency, said an IS-inspired group, Jemaah Ansharut Daulah, was suspected to be behind the attacks.
The father drove a bomb-laden car into the grounds of Surabaya Centre Pentecostal Church.
The mother and her two daughters – aged 9 and 12 – had bombs strapped to them and blew themselves up at Diponegoro Indonesian Christian Church.
The family’s sons – aged 16 and 18 – rode motorcycles into Santa Maria Catholic Church, and detonated explosives they were carrying. It was their attack that came first, at around 07:30 local time (6 am India time). The other two attacks followed five minutes apart, police said, according to the Jakarta Post.
TV pictures showed debris scattered around the entrance of one church.
Officials reportedly foiled attacks against other churches.
The blasts occurred before Sunday services began in the port city in the island of Java with 2.7 million people.
Police ordered the temporary closure of all churches in Surabaya, and canceled a large food festival in the city.
The bombings come days after Islamist militant prisoners killed five members of an elite counter-terrorism force during a 36-hour standoff at a high-security jail on the outskirts of the national capital, Jakarta.
“I heard a huge explosion at about 6.30 am (local time). I finished my shower and went out and saw five ambulances already arrived at the site. The church’s gate was burnt. Several people were down,” a resident who lives near the church told local media.
The road outside the church was blocked. Pictures sent by netizens show at least three injured people lying on the ground and a boy covered in blood being carried from the site.
Indonesia is the world’s largest Muslim-majority country and has seen a recent resurgence in homegrown militancy.
The country is home to significant numbers of Christians, Hindus and Buddhists but there are concerns over rising intolerance.
Extremists have mounted a series of attacks against Christians and other minorities in recent years.
Churches have also been targeted previously, including near-simultaneous attacks on churches there at Christmas in 2000 that killed about 20 people.
In January 2016 four suicide bombers and gunmen attacked a shopping area in central Jakarta.
In the early 2000s, Indonesia was rocked by terrorist attacks by affiliates of al Qaeda, including a bomb attack in Bali that killed 202 people, many of them foreign tourists.
The National Police have called on the public not to share graphic pictures and videos of the deadly Surabaya church bombings that occurred on Sunday morning to prevent fear from spreading.
Christians comprise 6.3 percent or about 23 million of Indonesia’s population of 238 million, according to a 2010 census, of which Protestants number 16.5 million and Catholics 6.9 million.