In its bulletin, the Philippine Institute of Volcanology and Seismology said the twin quakes were felt at 9:52 a.m. and 9:59 a.m.
The first tremor was recorded some 50 kilometers northeast, while the second was 36 km southwest of the island-town.
The quakes were also felt in Isabela province and mainland Cagayan, but there were no reported damage or injuries.
School principal Julieta Domingo of San Mateo town and private school president Salome Carino of Ilagan City, both in Isabela, said they felt the “split-second quake and thanked God no one was hurt.”
Fe Villanueva, a Gamu town resident, said she also felt the quake but said nothing has been damaged in their area.
LZB