A MAGNITUDE 6.4 earthquake struck offshore Sarangani, Davao Occidental on Wednesday, with the local volcanology agency classifying it as an aftershock of the magnitude 7.8 earthquake that hit the area in June. The quake struck at 12:14 p.m. about 37 kilometers south-southwest of Balut Island. Aftershocks from the June earthquake could continue in the coming weeks. The June earthquake killed more than 90 people and caused at least P1.47 billion in infrastructure damage, according to the latest disaster agency report. No tsunami warning was issued for Wednesday’s quake.