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 network.
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 years 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.
Indonesia was on high alert after bombings on Sunday by a single family targeted three churches in Surabaya, the capital of East Java province.
The mother targeted one church alongside her two daughters, aged nine and 12, while the father and two sons attacked two other churches.
The incident represented the first time a female suicide bomber had successfully carried out an attack, national police chief Tito Karnavian said. A 28-year-old woman had planned to bomb the Presidential Palace last year but was caught and jailed, he added.
The authorities originally said the family of six were among hundreds of Indonesians who had returned from conflict-hit Syria but have since said the family did not actually travel there.
The coordinated attacks killed 18 people, including the bombers, and injured more than 40. They were the deadliest bombings in Indonesia in more than a decade.