Indonesian authorities are threatening to move a community of displaced Shi'ite Muslims to another part of Indonesia if they refuse to convert to Sunni Islam.
About 165 Shia's have been camped out in a sports complex in East Java since August, after their village was stormed by about 500 people opposed to their beliefs.
One person died and several others were injured in the August 26 attack in Sampang district, where many homes were burnt to the ground.
Five people are reportedly awaiting trial for their role in the attack.
Amnesty International says the violence may have been incited by local Sunni leaders.
"They mobilised many of the villagers to attack the community," said Amnesty International's Indonesia campaigner, Joseph Benedict.
"What we heard is that there's been a lot of incitement against the Shia community for many months leading up to the attack and we're also aware that the police were aware of the attack before it happened."
Officials in East Java have told the group they will have to convert to Sunni Islam - the country's majority religion - by March, or face relocation.
Rights groups say religious intolerance, violence, intimidation are all on the rise in Indonesia.
According to local rights watchdog, the Setara Institute of Peace, attacks on religious minorities have increased steadily since 2009, with more than 370 acts of violence committed last year alone.
"The target especially is the Christian minority and the second is the Ahmadiyya and the third is Shia and the fourth is an Islamic sect - they're accused because they are deviant or heretic," said Bonar Tigor Naipsos, the institute's deputy director.
With elections due to be held next year, doubts have been raised over the government willingness to step in and resolve the situation.