A policeman stands guard following a bomb blast at a police station in Surabaya, Indonesia, on May 14 2018. Picture: REUTERS
A policeman stands guard following a bomb blast at a police station in Surabaya, Indonesia, on May 14 2018. Picture: REUTERS

Surabaya, Indonesia — A family of five, including a child, carried out the suicide bombing of a police headquarters in Indonesia’s second city, Surabaya, on Monday, police said, a day after a deadly wave of attacks on churches staged by another family.

The spate of bombings has rocked Indonesia, with the Islamic State (IS) group claiming the church attacks and raising fears about its influence in Southeast Asia as its dreams of a Middle Eastern caliphate fade.

Indonesia, which is set to host the Asian Games in just three months, has long struggled with Islamist militancy, including the 2002 Bali bombings that killed more than 200 people — mostly foreign tourists — in the country’s worst terror attack.

Security forces have arrested hundreds of militants during a sustained crackdown that smashed some networks. Most recent attacks have been low-level and have targeted domestic security forces. But that changed on Sunday as a family of six — including girls aged nine and 12 — staged suicide bombings of three churches during morning services in Surabaya, killing 18 including the bombers.

On Monday, members of another family blew themselves up at a police station in the city, wounding 10.

"There were five people on two motorbikes. One of them was a little kid," national police chief Tito Karnavian said.

"This is one family."

An eight-year-old girl from the family survived the attack and was taken to hospital, while her mother, father and two brothers died in the blast, he said.

The children were probably led to their deaths without a full awareness of their fate, said Ade Banani, of the University of Indonesia’s research centre of police science and terrorism studies. If a family believed in traditional roles, the father "has the power, so everyone has to obey", Banani said.

"The children probably don’t know what’s going on or don’t understand."

The father of the church suicide bombers was a local leader in extremist network Jamaah Ansharut Daulah (JAD), which supports IS. The second family was also linked to JAD.

"It ordered and gave instructions for its cells to make a move," Karnavian said of IS’s role in the church attacks.

Karnavian added that the bombings may have also been motivated by the arrest of JAD leaders, including jailed radical Aman Abdurrahman, and were linked to a deadly prison riot staged by Islamist prisoners at a high-security jail near Jakarta last week.