MANILA—A strong 6.1 magnitude earthquake struck off the coast of Laoag City at 4:26 p.m. Sunday, the Philippine Institute of Volcanology and Seismology said.

The quake hit at a shallow depth of 39 kilometers, 122 kilometers northeast of Laoag City.

It was felt at Intensity V in Pasuquin and Pagudpod, Ilocos Norte; Intensity IV in Paoay, Ilocos Norte; Calayan Island; Intensity III in Basco Batanes; Sinait, Ilocos Sur; Gonzaga and Camalaniogan, Cagayan; Manila City; Intensity II in Baguio City; Vigan, Ilocos Sur; and Intensity I in Santa, Ilocos Sur.

The Philippines sits on the Pacific Ring of Fire, a zone where continental plates collide causing frequent seismic and volcanic activity.