"There was an explosion at the Surabaya police headquarters at 8:50 a.m. local time," a spokesman of the East Java Police Senior Commissioner Frans Barung Mangera stated.
Mangera could not as yet provide information on whether the explosion had claimed lives but confirmed there were some victims in the incident.
"We confirm there are victims in the incident but whether they are killed or injured, please wait for further information," he noted, adding that the victims were police officers and civilians.
The police is still conducting investigation at the location.
Mangera has also confirmed that the bomb was carried in a vehicle.
"We are certain that this was a motorcycle," he asserted.
The explosion occurred after two motorcycles and a car stopped at the entry gate of the police headquarters.
East Java Deputy Police Chief Brigadier General Widodo Eko Prihastopo will check the location later on in the day.
"We will continue to update the information," Mangera added.
EDITED BY INE