Human Rights Watch on Sunday called on Indonesia to drop treason charges against five peaceful protesters, a day ahead of their expected trial in the remote province of Papua.

The New York-based rights watchdog said Indonesian security forces in October had used "excessive force" including batons and firearms to break up a pro-independence assembly in the provincial capital Jayapura, killing at least three people and injuring more than 90.

Eight police officers were let off with written warnings for disciplinary infractions but five Papuan leaders were charged with treason – and are expected to stand trial on Monday, it added.

"The Indonesian government should show its commitment to peaceful expression by dropping the charges against these five Papuan activists," the group's Asia deputy director Elaine Pearson said in a statement.

"It's appalling that a modern democratic nation like Indonesia continues to lock up people for organizing a demonstration and expressing controversial views," she added. Pursuing the trial would "only deepen the resentment that many Papuans feel against the government", Pearson said.

HRW also urged Indonesia to release at least 15 other Papuans, including independence leader Filep Karma, and about 60 other people mostly Maluku activists, over "peaceful acts of free expression."

Right groups accuse Indonesia of gross human rights abuses in Papua, a Melanesian-majority region rich in natural resources where poorly armed rebels have been fighting for independence for decades.

Jakarta denies the allegations but refuses to allow foreign media or aid workers into the remote eastern province to conduct independent inquiries.