A magnitude 5.8 earthquake struck 73 kilometers north-northwest (N 24° W) of Dalupiri Island, Calayan, Cagayan early Monday, April 28, according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS).

Based on monitoring, the earthquake occurred at 1:18 a.m. and had a depth of 48 kilometers. It was identified as an aftershock of the magnitude 5.5 quake recorded earlier at 12:54 a.m.

Reported intensities are as follows:

• Intensity V – Calayan, Cagayan
• Intensity IV – Pasuquin, Bacarra, and San Nicolas, Ilocos Norte
• Intensity III – City of Batac, Ilocos Norte

Instrumental Intensities:

• Intensity IV – City of Laoag, Ilocos Norte
• Intensity III – Aparri and Claveria, Cagayan; City of Batac, Ilocos Norte; Sinait, Ilocos Sur
• Intensity II – Gonzaga, Cagayan; Solsona, Ilocos Norte; City of Vigan, Ilocos Sur
• Intensity I – Peñablanca, Cagayan