Indonesian police arrested 200 people in Jakarta yesterday for participating in a rally to mark the West Papuan nationalist day.
It was the 55th anniversary of the 1 December first official raising of the Papuan Morning Star flag, when the indigenous people of the former Dutch New Guinea declared independence.
The Morning Star was subsequently banned after Indonesia took over, but an increasing number of global rallies have marked this anniversary in support of Papuans.
This year, non-Papuan Indonesians were among the hundreds who demonstrated in the capital and were blasted by water cannons, before police arrested 203 of them.
A public interest lawyer who was present, Veronica Koman, said demonstrators were roughed up by undercover police, and ten of those taken in by police suffered injuries.
Ms Koman said police did not cite any particular alleged breach of the law in making the arrests, and were creating excuses such as wanting to prevent traffic jams.
"The police will always find ways to forbid the demonstration," she said.
"This year alone, since April - April 2016 until now - there have been at least 4800 arrests."
The arrests followed an ongoing pattern of infringement of constitutional rights, she said.
"It's just basic freedom of expression. As long as Papua is still a part of Indonesia it means they still have the right to freedom of expression, and it's being violated systematically by the state."
Ms Koman said 14 demonstrators were also arrested in the Indonesian city of Yogyakarta.