MANILA, Philippines — A magnitude 5.3 earthquake shook the province of Batanes on Thursday morning, according to the Philippine Institute of Volcanology and Seismology (Phivolcs). Tectonic in origin, the tremor occurred at 6:28 a.m. some 177 kilometers (kms) north-west of the municipality of Sabtang, Phivolcs said. With a depth of 33 kms, the quake could trigger some aftershocks, although damage to infrastructure was unlikely, it said.