Sian Powell, Jakarta – Indonesian paramilitary police beat and kicked Papuan students yesterday in reprisals for the deaths of three policemen and an air force officer.

Human rights worker Albert Rumbekwan, from the Indonesian National Commission on Human Rights, said the police had blocked roads and were searching every vehicle.

"The Papuans, the young ones, have been taken and beaten, kicked, hit with guns and threatened," he said. "One of my men was beaten. Another two were threatened. Their cameras, their tape recorders and their notes on the chronology of events were taken."

Experts said the anger and frustration in Indonesia's easternmost province of Papua could soon boil over, fuelled by the armed forces' reprisals and resentment of Jakarta's rule. Indonesia's security forces, accused of a string of atrocities in the province, are expected to crack down harder than ever.

Indonesian police had arrested 57 people in connection with Thursday's riot. Others who had fled to the mountains would be hunted down, said police spokesman Kartono Wangsa Disastra.

"We will never stop hunting these people who have created havoc and murdered our officers," he said.

Nineteen security officers were seriously wounded and five protesters were hurt in the violence, he said, adding police had used rubber bullets and that reports of shootings with live bullets were false. "If we used live bullets they would all be dead," he said.

Thursday's riot on the outskirts of Jayapura was the most violent of the protests in Papua and Jakarta in recent months.

Protesters in Timika blocked a road for days last month as security guards were attacked with arrows and protesters apparently shot with bullets. The Sheraton hotel in Timika was later attacked.

The giant Freeport gold and copper mine in Timika has become a lightning rod for Papuan anger, according to International Crisis Group Southeast Asia analyst Francesca Lawe-Davies. "It's actually a set of protests long-organised by Papuan student groups, which is partly about (demanding) the closure of Freeport, but which channels a general sense of frustration," she said.

Papuans were concerned about human rights abuses, Ms Lawe-Davies said, along with the failure to discipline the military responsible for the breaches and the splitting of the province. "It reflects a generalised malaise about the failure of special autonomy," she said.

Mr Rumbekwan said people in the Abepura and Kotaraja districts on the edge of Jayapura were terrified. "Those who are guilty, those who are not guilty and not involved, everyone is considered the same," he said. "Brimob (the paramilitary police) are sweeping through the streets, and I think this is an act of revenge."