An Indonesian court on Monday indicted five Papuan activists for treason for raising an outlawed Papuan flag and declaring the region independent.

The men, who led a peaceful pro-independence celebration attended by 5,000 indigenous Papuans on October 19, face life in prison if found guilty.

"The defendants jointly tried to commit treason with the intention of allowing the country or part of the country to fall into the hands of the enemy," judge Jack L. Oktovianus at the Jayapura district court said.

"They acted together to declare Papua an independent region, which constitutes an act of treason."

Local TV footage had showed the men declaring the region's independence in the Papuan capital Jayapura and paramilitary police then shooting into the crowd and beating participants with batons and bare fists.

At least three people were killed and more than 90 injured in the chaos. Eight police officers were let off with written warnings for disciplinary infractions.

New-York-based Human Rights Watch on Sunday called for the cancellation of the trial.

"It's appalling that a modern democratic nation like Indonesia continues to lock up people for organising a demonstration and expressing controversial views," the group's Asia deputy director Elaine Pearson said in a statement.

Indonesia in 1969 took control of Papua, a former Dutch colony on the western half of New Guinea island, after a vote among a select group of Papuans widely seen as a sham.

Papuans, mostly indigenous Melanesians, have long accused Indonesia's military of violating human rights in the province and complain that the bulk of earnings from its rich natural resources flow to the capital.

Jakarta keeps a tight grip on the region through its military, which regularly clashes with locals, and foreign-based journalists are barred from reporting in the region.

More than 170 people are currently imprisoned in Indonesia for peacefully promoting separatism, most of them from Papua or the eastern Maluku islands, according to Human Rights Watch.