MANILA: A magnitude 6.4 earthquake struck off the province of Davao Occidental in the southern Philippines on Sunday morning, the Philippine Institute of Volcanology and Seismology (Phivolcs) said. There were no immediate reports of casualties or damage but several aftershocks were felt, Phivolcs said in its advisory. The epicentre was 126 km (78 miles) southeast of Jose Abad Santos town.