"The perpetrators numbered five to six," Papua Police Command spokesman Senior Commissioner Wachyono said when asked about the incident here on Saturday.
He said based on preliminary results of the investigation their motive was merely to disrupt security situation in Mimika.
He said the police were still investigating further the incident.
Wachyono said the police discovered a number of documents belonging to a separatist Free Papua Movement (OPM) group on the scene.
He said one of the document bears the signature of Teni Kualik the commander of the OPM`s National Liberation Soldiers (YPN) for Timika region.
The shooting of a pick-up truck L300 with a plate number DS 8229 MA occurred at around 3.21 local time on Friday (Oct 14).
Yana Heryana, Iip Abdul Rohman and Deden who were employees of PT Puri Fajar Mandiri were killed in the incident.
Attackers also shot PT Freeport Indonesia security car that came to respond to the incident.
Two passengers of the car namely First Private Thobias, a personnel from Infantry Batallion 754 Eme Neme Kangasi and Roy Makalele were hit in the hand and foot in the attack.
PT Freeport Indonesia meanwhile has expressed support to the police to investigate the case.
The company spokesman, Ramdani Sirait, said PT Freeport mourned the death of the three employees of its contractor in the incident.
He said the scene of the incident was the same as the one where the car carrying Daniel Mansawan and Hari Siregar was attacked and burned last April causing the two to die.
(T.E015/Uu.H-YH/HAJM/S012)
Editor: Priyambodo RH
Copyright © ANTARA 2011