Nearly three million minority Muslims in southern Philippines voted on Monday in a referendum on autonomy, a move that is aimed at ending decades of conflict and granting them greater control over their land and natural resources.
Residents in Mindanao region are being asked if they back a plan to create a self-administered area.
A clear "yes" vote is widely expected, which would grant executive, legislature and fiscal powers to the region.
Mindanao, the Philippines' second-biggest island, has mineral deposits worth about $300 billion, or 40 percent of the country's reserves, according to government estimates.
It also has among the highest rates of poverty after decades of conflict, which has killed about 120,000 people and forced more than two million from their homes, according to human rights activists.
Philippine President Rodrigo Duterte has backed the new region, saying it will bring peace and wealth in Mindanao, his home island.
The results of Monday's vote are due to be declared later this week.
A "yes" vote would mean the area will have complete authority over land reforms and indigenous peoples' rights.
