Philippine President Rodrigo Duterte yesterday approved a long-awaited law to allow minority Muslims in the south to start moving towards self-rule by 2022, in bid to defuse a half-century of separatist conflict. Duterte signed the measure into law after a visit to a southern city, his spokesman, Harry Roque, told reporters.

Ebrahim Murad, chairman of the separatist Moro Islamic Liberation Front (MILF), said he was confident the law would help bring splinter separatist groups back into the political fold.

The Bangsamoro Organic Law, as the measure is known, has broad public backing, making it harder for foreign militants to form alliances and win support, he told reporters.

"All these splinter groups are a result of the frustration with the peace process. The moment the small groups no longer accept the foreign elements, they can no longer come [to the Philippines]."

The Bangsamoro area includes part of the Philippines' second-largest island of Mindanao, and a chain of dozens of small islands to the west notorious for piracy and banditry. An estimated five million Muslims live in the region, which has the predominantly Catholic nation's lowest levels of employment, income, education and economic development. The momentum behind the autonomy process was "a long-awaited dream coming true", said Jesus Dureza, Duterte's top peace adviser.

The new law gives the new entity, Bangsamoro Autonomous Region in Muslim Mindanao, political and economic powers that successive governments have promised separatists, in order to halt conflict that has killed about 120,000 people, displaced 2 million.