According to Frans Barung Mangera, the explosion had occurred at 8:50 am local time (01:50 GMT) at the main police office.
Members of one family conducted an attack on Police HQ in Indonesian city of Surabaya, according to police.
According to the CCTV footage from the scene, the assailants arrived on the motorbikes to the police HQ's security checkpoint before detonating an explosive devise, the Jakarta Globe newspaper reported.
The recent deadly incident at the local Police HQ is a fourth explosion that took place in Surabaya over the last days and the fifth one in the eastern part of Java island. Also on Sunday, another explosion occurred at the apartment building in the town of Sidoarjo, which borders Surabaya, according to the Jakarta Post newspaper. The blast was presumably caused by an accidental detonation of the explosive device. Three people were killed in the incident.