MANILA, Oct. 3 -- The Philippine Institute of Volcanology and Seismology (Phivolcs) said Friday the "onland extension of the newly-named Bogo Bay Fault" generated the Sept. 30 magnitude 6.9 offshore Cebu earthquake.

The Phivolcs team observed fault scarps, open cracks, and small pressure mounds within a 2-meter-wide deformation zone in Sitio Looc, Barangay Nailon, Bogo City.

"Initial field mapping recorded about 200 meters of surface rupture, while drone surveys revealed the fault may extend up to 1.5 kilometers, showing signs of right-lateral movement," Phivolcs said in a social media post.

It added that field verification is ongoing to determine the full extent of the rupture.

Meanwhile, as of 8 p.m. Friday, the Phivolcs recorded 4,...