Manila, Oct 17 : The Philippine Institute of Volcanology and Seismology downgraded the magnitude of an offshore earthquake that struck Surigao del Norte province in the southern Philippines on October 13 to magnitude 6 from 6.2.

In an updated seismic report, the institute said the tremor, which occurred at 7:03 a.m. local time (2303 GMT), struck at a depth of 28 km, approximately 13 km southeast of the municipality of General Luna in the Mindanao region.

The institute said that the tectonic quake will trigger aftershocks and cause significant damage.

The tremor was also felt in neighbouring provinces in the Mindanao region and the central Philippines. There were no immediate reports of casualties or damage.

The tremor is the latest powerful earthquake that rocked the archipelagic Philippines. On September 30, a 6.9-magnitude earthquake hit Bogo City and nearby areas in Cebu province in the central Philippines, killing 76 people, the National Disaster Risk Reduction and Management Council said.

Twin offshore tremors of magnitude 7.4 and 6.8 rocked Davao Oriental province in the southern Philippines on October 10, killing eight people.

A 6.0-magnitude earthquake struck near Bogo, Cebu, in the central Philippines, again in the early hours of October 13, Xinhua news agency reported.

Since then, the archipelago has been rocked by magnitude 4 and 5 earthquakes, triggering landslides and displacing thousands of villagers.

The archipelagic Philippines has frequent seismic activities due to its location along the Pacific "Ring of Fire".

The Philippines is one of the most disaster-prone countries in the world, positioned along the "typhoon belt" and within the Pacific Ring of Fire, making it highly vulnerable to several catastrophic events, including volcanic eruptions, earthquakes, and typhoons

The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel.

/IANS