FILIPINO President Rodrigo Duterte has asked Moro — Muslim Filipino — and communist rebels to join the fight against the country’s Isis affiliate.

The unprecedented move on Sunday came ahead of a Supreme Court challenge by six opposition congress members yesterday to Mr Duterte’s declaration of martial law in the southern island of Mindanao.

Troops are fighting Isis-affiliated Abu Sayyaf extremists who seized the city of Marawi, the largest city in the province of Lanao del Sur on the island, two weeks ago.