A suicide bombing at a police headquarters in the Indonesian city of Surabaya on Monday was carried out by a family of five riding on two motorbikes, police say.
It came after another family carried out bomb attacks on three churches on Sunday, in an attack claimed by the Islamic State (IS) group.
An eight-year-old girl survived the latest attack, police say.
Indonesia is the world’s most populous Muslim-majority country.
The archipelago, home to 260 million people, has seen a resurgence of Islamist militancy in recent months, and the attacks in Surabaya have raised concerns about the potency of jihadist networks.
Video footage of the latest attack on the police headquarters shows two motorbikes approaching a checkpoint just before the blast. Six civilians and four police officers were injured, authorities said.
What preceded the latest attack?
Indonesia was on high alert after bombings on Sunday by a single family targeted three churches in Surabaya.
A mother and two daughters, aged nine and 12, blew themselves up at Diponegoro Indonesian Christian Church, while the father and two sons targeted two others.
In the first attack, the sons – aged 16 and 18 – rode motorcycles into Santa Maria Catholic Church at around 07:30 local time (00:30 GMT) and detonated explosives they were carrying.
After reportedly dropping his wife and daughters off to carry out their attack, the father, Dita Oepriarto, drove his own bomb-laden car into the grounds of Surabaya Centre Pentecostal Church, police said.
Authorities originally said the family of six were among hundreds of Indonesians who had returned from conflict-hit Syria but have since said that the family did not actually travel there.
The coordinated attacks killed 13 people and injured more than 40. They were the deadliest bombings in Indonesia in more than a decade.
Police say Oepriarto was the head of local branch of Jemaah Ansharut Daulah (JAD), an Indonesian IS-inspired network.