At least two people died and another four were heavily injured after a powerful explosion rocked Indonesia's main island of Java on Saturday.
About a dozen of houses, situated near the spot 50 kilometres away from country's second city of Surabaya, have been destroyed.
The blast was probably caused by a bomb, immediate reports showed.
A spokesman for the Indonesian police told pieces of aluminium were discovered near the spot, which proves there was placed an explosive device.
The case is still under investigation.