Amnesty International says a Papuan human rights lawyer, defending a tribal leader accused of separatist activities by Indonesian authorities, has been attacked.
Amnesty says it has concerns for the safety of Anum Siregar
The rights group says the lawyer was attacked on the way back to her hotel from a court hearing.
The attacker, armed with a knife, stole her bag and injured her hand before fleeing.
Ms Siregar and another lawyer had travelled to Wamena to represent the Head of the Lani Besar Tribal Council, at a pre-trial hearing.
Amnesty says both felt they were being monitored.
They were challenging the Tribal Council leader's arrest and detention which they believe to have been unlawful.
Areki Wanimbo was arrested last month after meeting two foreign journalists who were making a documentary on the separatist movement.
He was accused of supporting separatist activities and charged with "rebellion" under the Criminal Code.