MANILA, Philippines—(UPDATE) A 5.6 magnitude earthquake struck off General Santos City at 5:21 p.m. Thursday, the US Geological Survey said.

There were no immediate reports of damage or injury.

The undersea quake was located 77 kilometers (48 miles) east-southeast of General Santos City at a depth of 123.8 kilometers.

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