Minority Muslims in the southern Philippines cast votes on Monday in a long-awaited referendum on autonomy, the culmination of a peace process to end decades of separatist conflict in a region plagued by poverty, banditry and Islamist extremism.
Some 2.8 million people in the volatile Mindanao region are being asked if they back a plan by separatists and the government to create a self-administered area known as Bangsamoro, or "nation of Moros", referring to the name Spanish colonialists gave to the area's Muslim inhabitants.
A clear "yes" vote is widely expected, which would grant executive, legislature and fiscal powers to a region where more than 120,000 people died a four-decade conflict that left it one of Asia's poorest and at risk of infiltration by radical groups.
The central government would continue to oversee defense, security, foreign and monetary policy, and appoint a transition authority run by the Moro Islamic Liberation Front (MILF), the separatist group expected to dominate the new setup after a 2022 election.
"We are confident that 'yes' will win," MILF chairman Murad Ebrahim told CNN Philippines on Monday.
"If there is no manipulation, no intimidating, there will be overwhelming approval," he added.
That would be a much-needed boost for Philippine President Rodrigo Duterte, who remains a hugely popular personality among Filipinos but has so far struggled to make inroads on his ambitious policy agenda.
Though the Bangsamoro plan was negotiated by his predecessors, Duterte, a mayor in Davao City in Mindanao for 22 years, is credited with ensuring it got the support of Congress, which the previous administration was unable to secure.
A result is expected by Friday. Duterte last week urged voters to approve the plan and show they wanted peace, development and a local leadership that "truly represents and understand the needs of the Muslim people".
The plan's advocates say it would address what are the predominantly Catholic country's lowest levels of employment, income, education and development, which experts say are exploited by pirates, kidnapping gangs and armed groups that have pledged allegiance to Islamic State.
The MILF has denounced extremists and said disillusionment over the slow progress towards devolution was a factor behind a 2017 occupation of Marawi City by rebels loyal to Islamic State, which the military took five months of ground offensives and devastating air strikes to defeat.
The whole of Mindanao has since been under martial law.
The MILF and the government hope autonomy would lead to greater investment in infrastructure and natural resources, and allow for expansion of fruit and nickel exports and development of a palm oil industry.