Jakarta – The Papua regional police said Wednesday they have yet to identify who was behind two mortar bombs set off in a concession area run by PT Freeport Indonesia in September last year, despite having evidence in hand.

"We are still investigating the mortar bomb case that occurred on Freeport grounds. We've yet to name suspects and it looks like we won't be able to," Papua Police chief Insp. Gen. Bagus Ekodanto told a recent press gathering.

Ekodanto declined to mention the challenges investigators faced, but reiterated the police had gathered all available evidence and were cooperating with the National Police forensic lab.

"The police are still investigating the case, no doubt, in accordance with our investigatory procedures," he said. It was earlier reported that members of an unidentified group had set off two explosives on a highway leading to a gold and copper concession area run by PT Freeport Indonesia, a unit of US mining giant Freeport McMoRan, in Papua.

One of the mortar bombs was set off at a gas station at Mile 50. The second bomb, one of two explosives placed under a bridge crossing the Kabur river on Mile 39, was also set off. Neither explosion caused any significant damage. (amr)