Two weak earthquakes struck off Mamburao on Thursday, the Philippine Institute of Volcanology and Seismology said.

At 10:36 a.m., a 1.9 magnitude tremor hit 37 kilometers northwest of Mamburao at a depth of 85 kilometers.

Earlier at 6:54 a.m., a 2.7 quake occurred 57 kilometers northwest of Mamburao. It has a depth of 94 kilometers.

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