A 5.1 magnitude earthquake hit off Southern Mindanao shortly after midnight Saturday, hours after two other moderate quakes jolted the Philippines, the US Geological Survey said.

There were no immediate reports of damage or injuries from the tremors, the latest of which occurred at 12:18 a.m. Saturday about 75 kilometers east-southeast of General Santos City. It had a depth of 53.7 kilometers.

At 4:37 p.m. Friday, an earthquake measuring 5.8 on the Richter scale struck 150 kilometers east-southeast of Davao City at a depth of 111.5 kilometers.

About 10 hours earlier, a 4.6 magnitude quake hit 75 kilometers west-northwest of Basco, Batanes. It struck at a depth of 35 kilometers.

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