MANILA, Philippines — A magnitude 5.1 earthquake shook the province of Davao Oriental early Sunday, the Philippine Institute of Volcanology and Seismology (Phivolcs) said. The tremor, which occurred at 7:13 a.m., was located 198 kilometers (kms) southeast of Governor Generoso town, Phivolcs said. With a depth of 40 kms, the quake was tectonic in origin. While damage to infrastructure was unlikely, aftershocks were possible, it added.