Suspected separatist rebels killed four people including an army officer in Indonesia's restive Papua province yesterday, the first such attack in almost four months, police said. The unidentified attackers blocked a road near the provincial capital Jayapura, opened fire on passing vehicles and then attacked the shocked passengers with machetes, police said. An army officer and three others were killed, while seven were injured, Papua provincial police spokesman Wachyono told reporters. According to intelligence information, the Morning Star flag was found thrust into the ground by the roadside," he added, referring to the outlawed flag of Papuan independence. Jayapura police chief Imam Setiawan said authorities suspected the pre-dawn attack was the work of the rebel Free Papua Movement (OPM), which has been fighting for independence for decades. But Papuan Customary Council chairman Forkorus Yaboisembut, a community leader, said he believed the police or military were responsible. "This is the work of some other group that seeks to discredit the OPM. I suspect the police or military could be behind this," he told AFP. The attack came a day after election-related mayhem left 17 people dead in Puncak district, hundreds of kilometers (miles) southwest of Jayapura. Police said the two incidents were not related. Armed with machetes, rocks and arrows, mobs of people affiliated to rival candidates for the job of district chief clashed in the remote town of Illaga, local police chief Alex Korwa said. "We've deployed dozens of police and military to secure the area. The situation is tense but under control," he said, adding that investigations were ongoing. The recently created district, which is only accessible by plane, is scheduled to hold its first local elections on November 9. The ambush near Jayapura was the first of its kind since April, when two people were killed and two were injured in separate incidents involving vehicles belonging to US mining giant Freeport McMoRan. An Australian employee of Freeport and a local security guard were shot dead in July 2009 on a road near the company's operations in Mimika district. The Freeport mine sits on some of the world's richest gold reserves and is the largest single taxpayer to the Indonesian government. It has also paid hundreds of thousands of dollars a year to military and police officers in Papua. US diplomatic cables released by anti-secrecy website WikiLeaks last year said the Indonesian military allegedly ran a "virtually autonomous governmental entity within the province", with links to illegal logging. Pro-independence militants have waged a long-running insurgency against Indonesian rule in Papua. The rebels claim the process by which Indonesia annexed Papua in 1969 was illegitimate, and accuse Jakarta of exploitation and oppression. Indonesia rejects the allegations and has tried to address P apuan concerns by granting the region special autonomy.