The Philippine Institute of Volcanology and Seismology (Phivolcs) detected a magnitude 5.7 earthquake in Davao Occidental on Friday evening, Aug. 27.
Phivolcs said the epicenter of the earthquake was traced at 19 kilometers (km) southwest of Sarangani town in Davao Occidental province at around 6:22 p.m.
It was initially measured at magnitude 5.6 but Phivolcs later revised it to 5.7.
The earthquake was "moderately strong" at Intensity IV in Glan, Alabel, Kiamba, Maasim, Malapatan and Malungon, Sarangani; General Santos City; Don Marcelino, Jose Abad Santos, Malita, and
Sarangani, Davao Occidental; and Polomolok, South Cotabato.
It was "weak" at Intensity III in Banga, Koronadal City, Lake Sebu, Tampakan and Tupi, South Cotabato; and Bagumbayan, Kalamansig and Lebak, Sultan Kudarat.
Meanwhile, it was slightly felt at Intensity II in Davao City; Norala, Santo Niño, Surallah and Tantangan, T'boli, South Cotabato; Kidapawan City, Kabacan and Makilala, Cotabato; Isulan and
President Quirino, Sultan Kudarat; and Digos City, Matanao and Santa Cruz, Davao del Sur.
The tremor was "scarcely perceptible" at Intensity I in Zamboanga City; Lambayong and Sen. Ninoy Aquino, Sultan Kudarat; and M'lang, Cotabato.
Phivolcs said the earthquake was tectonic in origin, which means the tremor was caused by the movement of an active fault near the area.
It warned that aftershocks are likely to occur.