The East Java police spokesman has reported that attacks have cost lives of at least 13 people and that 40 have been transferred to hospital, including two police officers.
According to Karnavian, the father of family was the bomber at the Surabaya Pentecostal Church, while two male teenage relatives blew themselves up at Saint Mary Immaculate Catholic Church.
They are believed to have been inspired by ISIS and were likely members of Ansharut Daulah, an Indonesian terrorist group affiliated with ISIS.
"The husband drove the vehicle, an Avanza, that contained explosives and rammed it into the gate in front of that church", East Java police spokesman Frans Barung Mangera told reporters at the regional police headquarters in Surabaya.
Police in Indonesia have revealed that members of the same family were behind suicide bomb attacks on 3 churches on Sunday.
In line with Karnavian's chronology of occasions, which does not line up with the sequence Mangera beforehand supplied to the state-run Antara news agency, the daddy, recognized as Dita Sopriyanto, drove a van to the Indonesian Christian Church and dropped off spouse Puji Kuswat and their 9- and 12-year-old daughters.
At least seven people plus the six bombers died in the attacks in Surabaya, according to police. Religious minorities in Indonesia, especially Christians, have been repeatedly targeted by militants.
However, Malaysia [VIDEO]and Indonesia have seen plenty of Islamist violence in the past, and Muslim-majority areas in southern Thailand and The Philippines are now embroiled in deadly insurgencies that include ISIS-like organizations.
"This act is barbaric and beyond the limits of humanity, causing victims among members of society, the police and even innocent children", President Joko Widodo said during a visit to the scene of the attacks.
Zarif embarks on journey to save nuclear deal by first visiting China
Iran has claimed its nuclear program is for civilian purposes and denies supporting extremists in the region. Iran's Supreme Leader Ayatollah Ali Khamenei has called the U.S. withdrawal "impudent" and "worthless".
In Jakarta, the Indonesian Church Association condemned the attacks. That blast was followed by a second explosion minutes later at the Christian Church of Diponegoro and a third at the city's Pantekosta Church, Mangera said.
The archipelago nation of some 17,000 islands has long struggled with Islamic militancy and has suffered a series of attacks in the past 15 years - including the 2002 Bali bombings that killed 202 people, mostly foreign tourists, in the country's worst-ever terror attack.
"At first officers blocked them in front of the churchyard, but the woman ignored them and forced her way inside". There was no immediate claim of responsibility.
"I saw two men riding a motorbike force their way into the churchyard".
"Suddenly, she hugged a civilian, then [the bomb] exploded", said the eyewitness, who identified himself as Antonius.
Police there have stepped up the alert for similar attacks.
Days ago, a prisoner and five police officers were killed in clashes at a high-security jail during which Islamist inmates took an officer hostage. A new threat has emerged in recent years, inspired by IS attacks overseas.
Almost 90 percent of Indonesians are Muslim, but the country is also home to sizeable communities of Hindus, Christians, Buddhists, and people who adhere to traditional beliefs.