Inside the Philippine ghost city of Marawi, destroyed by war

Martial law has been in place in Mindanao since an extremist alliance overran Marawi City in 2017 and occupied it for five months, in what was the Philippines' fiercest and longest conflict since World War Two.

The city saw fierce fighting between the Filipino army and Islamic State militants who declared an Islamic caliphate before heavy fighting left much of the ruin-hit city a ghost city.

A predominantly Muslim area of the southern Philippines has since returned a resounding "Yes" in a referendum on greater autonomy, boosting hopes for peace in one of Asia's most conflict-torn regions.

The vote in Mindanao came at a critical time for the Philippines, which saw disillusioned armed factions break away and follow other armed groups in pledging allegiance to Islamic State.

That has stoked fears that fighters fleeing Iraq and Syria would join radicals from Malaysia and Indonesia in gravitating to Mindanao to capitalise on porous borders, jungles and mountains, and an abundance of arms.