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.
The moment a suicide bomber attacked Polrestabes Surabaya. This is the 5th bomb since yesterday.pic.twitter.com/buY6pOZLMl— Richard Allen (@iA7med08) 14 мая 2018 г.
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.
"We can't be open up all details yet because we are still identifying victims at the scene and the crime scene is being handled," East Java Police spokesman was quoted as saying by Reuters. Meanwhile, the police have already found the links with the Sunday attacks on churches in Surabaya.
“Similar types of explosives were used,” Frans Barung Mangera said. “Our personnel are identifying the victims. So far, we have accounted for seven victims. We are still collecting data,” East Java Police spokesman told reporters.
On Sunday, alleged Daesh-linked family of suicide bombers, including two young daughters, staged deadly attacks at three churches in Surabaya during Sunday services. At least 14 have reportedly died as a result of the attack with more than 40 injured, local media 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.