Pekanbaru, Riau, Oct. 6 -- Police in Riau Province are investigating the cause of an explosion and fire at PT Kilang Pertamina Internasional's Refinery Unit II in Dumai, which damaged a key production unit.

A forensic team from the Special Crimes Division (Ditreskrimsus) and the police forensic laboratory (Labfor) has been on-site since Thursday (Oct. 2) to examine the blast area. Investigators have also begun questioning refinery employees.

"The forensic team and Pertamina staff are already at the scene," Riau Police Spokesperson Senior Commissioner Anom Karibianto said in Pekanbaru on Sunday.

He explained that the investigation could only begin once the area was declared safe and all flames were fully extinguished.

"We have to wait ...