Banjir Ambarita, Jayapura – Two employees of mining giant Freeport were killed in Papua after the car they were traveling in overturned and caught fire, a company spokesman said on Friday.

Freeport spokesman Ramdani Sirait said the incident occurred outside of the company's mining area at about 6:15 p.m. on Thursday. The two company employees were security manager Daniel Mansawan and security officer Aris Siregar, he said.

Police sources have said they found spent bullets at the scene indicating that the car might have overturned after it had been shot. "We are assisting the police in their investigation of the incident," Ramdani said, declining further comment. Papua Police spokesman Sr. Comr. Wachyono was not immediately available for comment.

Early on Friday, hundreds of Freeport security employees gathered in front of the regional legislature in Timika, in a show of support for their two deceased colleagues.

Paulus Kogoya, coordinator of the event, said that since 2009, four members of the Freeport security department had been killed and dozens of others injured but none of the perpetrators had been found or punished.

"As their colleagues, we want to remind management – and the outside world – that between 2009 and 2011, it has been members of the security department who have been the victims," Paulus said.

"We are concerned by this incident and demand that this case be comprehensively investigated in line with prevailing legal procedures." The demonstrators held a joint prayer session and also demanded that the perpetrators be found.

"If not, we will take the bodies of our colleagues and bury them in the front square of the Freeport office in Kuala Kencana," Paulus said.

Demianus Dimara, a Freeport vice president, asked employees to return to work while awaiting the results of autopsies on the two victims, which will be performed at Tembagapura Hospital.

The incident occurred just a day after shots were fired at another company car, wounding two Freeport employees. Police said on Friday that they had found empty bullet cartridges at the scene of the shooting, at mile 37 on the road leading to the mine.

The Freeport mining complex and its employees have often been targeted by snipers. Police have alleged that Papua separatists are behind the attacks, claims the separatists deny.

In January, gunmen ambushed and fired at a convoy of vehicles carrying Freeport employees and family members on the highway between the mine and Kuala Kencana, injuring nine.

The injured included an American and a South African who had been working at the Grasberg gold and copper mine, the teenage daughter of a mine employee, as well as four Mobile Brigade (Brimob) police officers on security detail.

The Papuan mine is run by a subsidiary of US mining giant Freeport McMoRan Copper & Gold.

[Additional reporting from Antara, AP.]