A human rights group in the Indonesian province of Papua says police, church and government officials have to show leadership or violence in the Highlands town of Timika will escalate.
This follows the killing of two migrants in an attack that left five others hurt.
The latest deaths come after a three day battle in Timika in which four Amungme tribespeople were killed in fighting between supporters and opponents of Jakarta's plan to split Papua into three.
That plan was shelved last week after the fighting.
A spokesman for the human rights group, Elsham, John Rumbiak, says leaders need to step in to ease the growing tension.
"If there is no effort, especially calling on the leaders of these migrant members, as well as the religous leaders and the military commanders and local government in Timika to intervene to peacefully resolve this problem,the situation will escalate, even to become a religious conflict like in the Maluku."