Quake-related deaths in Philippines reach 20
President Rodrigo Duterte was in his hometown Davao City when the quake struck but he is safe.
Many houses and structures in Mindanao were destroyed in the series of earth quakes.
The office of President Duterte has instructed related agencies to provide the maximum possible support to areas hit by the disasters.
The Philippine Institute of Volcanology and Seismology (Phivolcs) advised locals to stay outside of houses and buildings for fear of strong aftershocks./.