Additional police and military forces are being sent to beef up security along a road in Papua that has seen a string of deadly attacks in recent days.

"We have decided to increase enforcement measures to restore security," said National Police spokesman Brig. Gen. Sulistyo Ishak on Thursday. He did not disclose how many 'special forces' would be sent.

At least 15 people, most of them police, have been killed or wounded along the 65-kilometer road from the town of Timika to the Grasberg complex owned by US mining giant Freeport McMoRan.

The Indonesian military and the National Police have openly disagreed about who is behind the attacks. Speculation has focused on the separatist Free Papua Movement (OPM), rogue soldiers or groups trained by the military.

Prominent human rights activist Usman Hamid said the fact that the attacks have been scattered along the roadway will make it harder to pinpoint their source. But he said the apparently coordinated moves from one site to another are probably too sophisticated for the OPM.

"They do not have strong organizational skills therefore it is hard to imagine that they can create such systematic chaos," said Usman, who heads The Commission for "the Disappeared" and Victims of Violence (KONTRAS).

"It is possible the violence is to attract international attention to Papua," he added. (AP, JG)