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.