The fourth suicide bombing attack occurred 12 hours later on May 14, when a family of five - two parents and three children - rode two motorcycles into the parking lot of the Surabaya police headquarters and detonated explosives concealed on their bodies and on the motorcycles.
The Islamic State group claimed responsibility for the suicide bombing of a police headquarters in Indonesia's second city Surabaya Monday, according to the SITE monitoring group. A girl aged 8 survived this attack in which four police officers and six civilians were injured.
The bombings, which have since been claimed by the Islamic State, are the deadliest terror attacks to place in Indonesia since 2005, leaving dozens of people dead and injured.
Jakarta police placed the capital and surrounding areas on high alert, while the transportation ministry warned airports to be on guard. It didn't mention anything about families or children taking part and said there were only three attackers. Indonesian security forces dealt with them fairly effectively.
Gen. Tito Karnavian, chief of the National Police, said the family suspected in Sunday's attacks had recently returned to Indonesia after being deported from Syria.
Concerns about sectarian intolerance have been on the rise, with churches targeted in the past.
A spokesman for Secretary-General Antonio Guterres issued a statement saying he was "appalled" at reports that children were used in Sunday's attacks.
"(The Secretary General) reiterates the support of the United Nations to the Government and people of Indonesia in their efforts to fight and prevent terrorism and violent extremism, including through the promotion of pluralism, moderation and tolerance", the statement said.
Christians, many of whom are from the ethnic Chinese minority, make up about 9 percent of Indonesia's 260 million people.
Police believe the suicide bombing father Oepriarto was the head of JAD in East Java. Around 10 per cent of the population is Christian.