CAGAYAN DE ORO, Philippines – A magnitude 6.7 earthquake shook Surigao del Sur province and other parts of Mindanao at 3:39 am on Monday, December 4.

It was one of hundreds of aftershocks, and the strongest so far, since the magnitude 7.4 earthquake struck off the coast of Hinatuan, Surigao del Sur, on Saturday night, December 2.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said the aftershock was recorded at 3:49 am, some 63 kilometers south-southeast of Cagwait town, also in Surigao del Sur. It had a depth of 10 kilometers.

There is no tsunami threat, Phivolcs said in an advisory.

Phivolcs data showed that the aftershock was strongly felt in the Caraga and Davao regions, and rattled residents as far as Cagayan de Oro in Northern Mindanao.  It was felt at Intensity IV in Nabunturan in Davao de Oro, Bislig City in Surigao del Sur, and Surigao City in Surigao del Norte, according to Phivolcs.

Phivolcs-Northern Mindanao Director Marcial Labininay told local broadcaster Magnum Radio in Cagayan de Oro that they have recorded more than 900 aftershocks since the magnitude 7.4 earthquake, as of 3 pm on Sunday, December 3.

“It could be more than a thousand by now,” Labininay said of the strong 3:39 am aftershock.

Aftershocks are common seismic occurrences, which take place after a stronger earthquake. They weaken in both intensity and frequency as time passes. – Rappler.com