The spate of bombings has rocked Indonesia, with the Islamic State group claiming responsibility for the church attacks and raising fears about its influence in Southeast Asia even as its dreams of a Middle Eastern caliphate fizzle.
Indonesia has long struggled with Islamist militancy, including the 2002 Bali bombings that killed over 200 people in the country's worst-ever terror attack.
Security forces have arrested hundreds of militants during a sustained crackdown that smashed some networks, and most recent attacks have been low-level and targeted domestic security forces.
But that changed Sunday as a family of six - parents, two teenage boys and two young girls - staged suicide bombings of three churches during morning services in Surabaya, killing 14.
Yesterday, members of another family attacked a police station in Surabaya, wounding 10. "There were five people on two motorbikes," police chief Tito Karnavian said. "One was a little kid, and this is one family."
An eight-year-old girl from the family survived and was taken to hospital while her mother, father and two brothers died in the blast.