Participants of the Papuan Congress in the provincial capital of Jayapura were shocked at being greeted at the venue by five armored vehicles and hundreds of heavily armed police and military officers, an attendee of the congress said on Wednesday.

"Three tanks belong to the Mobile Brigade (Brimob) of the Papua Police and the others are the military's," a participant named Oktovianus told the Jakarta Globe.

The meeting, held annually to push for the rights of indigenous Papuans among the many disparate tribes there, has been ongoing since Monday. More than 5,000 participants from 234 tribes in Papua have been in attendance. The event was scheduled to enter its last day on Wednesday at 9 a.m., but as participants arrived at the field in Padang Bulan Abepura where the congress has been held, they were greeted by the show of force from the police and military, Oktovianus said.

He added that the unannounced and heavy security presence unnerved some participants but that scheduled events went on as planned.

"The congress must go on because this is what every indigenous Papuan from Sorong to Merauke wants," he said. "The congress discussed the rights of the indigenous Papuans, especially political rights," Oktovianus said.

Organizers, he added, had notified the Coordinating Ministry of Political, Legal and Security Affairs about the congress well in advance. "The central government had been informed about the event, as well as the National Police and the military, two weeks before the congress."

However, he said, no permission had been granted by any of those institutions to hold the event. "The worst possibility is that we will be forcefully dismissed, but we hope everything is going to be fine," he said.

Andreas Harsono from Human Rights Watch urged the military not to use violence. "The Human Rights Watch condemns any forms of violence because violence does not solve the problem," Andreas said.

"The congress participants may speak of sensitive issues but they do it peacefully, no chaos, and no one is harmed," he said, adding that according to Indonesian law any form of gathering is allowed as long as the police are notified.

"I know such laws do not seem to apply in Papua but I ask the police not to discriminate the Papuans because they are also part of Indonesia," Andreas said.