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. Police blamed an Islamic State-inspired group.
An eight-year-old daughter 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 but the scale of the attacks in Surabaya has raised fresh 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, the authorities say.
The young girl who survived had been wedged between her mother and father on the motorbike as they carried out the attack. CCTV footage shows her stumbling around after the blast.