There was no immediate claim of responsibility after the latest suicide bombing.
President Joko Widodo strongly condemned the terrorist attacks in East Java, saying they were "beyond humanity measures". Indonesian National Police chief Gen. Tito Karnavian described the attacks as a reprisal for Indonesia's prosecution and imprisonment of the Jemaah Ansharut Daulah leadership and said that all three families implicated in the blasts had been friends. Police blamed an Islamic State-inspired network. The top security minister, Wiranto, who uses one name, said the government will attempt to hasten passage of an updated anti-terrorism law that has languished in parliament.
The militant group is part of a "second wave" of terrorist groups to be active in Indonesia, according to Hugo Brennan, senior Asia analyst at Verisk Maplecroft, a risk consultancy firm.
The archipelago nation of some 17,000 islands has long struggled with radical militancy, including the 2002 Bali bombings that killed 202 people - mostly foreign tourists - in the country's worst-ever terror attack.
Separately on Sunday, three members of another family were killed when homemade bombs exploded at an apartment in Sidoarjo, a town bordering Surabaya, police said. The third was detonated outside the Surabaya Central Pentecost Church.
Earlier in the morning his sons, ages 16 and 18, had ridden motorcycles into Santa Maria Catholic Church and detonated their explosives. Based on their remains, Karnavian said the mother and daughters were all wearing explosives around their waists.