MANILA, Philippines (2nd UPDATE) - A strong earthquake hit parts of Bicol region at 12:41 a.m. on Saturday.
The Philippine Institute of Volcanology and Seismology (Phivolcs) reported that a magnitude 6 earthquake hit the Bicol area with the "Sibuyan Sea Fault" as the possible source.
The earthquake, tectonic in origin, had the following intensities:
Intensity V- Lignon Hill, Legaspi
Intensity IV-Masbate City, Sorsogon City, Irosin, Sorsogon and Sto. Domingo, Albay
Intensity II- Cebu City.
Phivolcs chief Renato Solidum reported over radio dzMM that the earthquake was followed by 2 aftershocks -- magnitude 4.1 at 1:45 a.m. and magnitude 3.6 at 2:25 a.m..
Solidum and the National Disaster Risk Reduction and Management Council said that there were no reports of damage from the tremors.
The US Geological Survey (USGS) recorded the earthquake at magnitude 5.6 in an area near Masbate.
The USGS said the earthquake was 75 kilometers northwest of Masbate, 85 kms west southwest of Legaspi, 95 kms south of Naga, and 300 kms southeast of Manila.
It said the quake had a depth of 35.5 kms.
Some citizens in Bicol reported on twitter that they felt the strong quake.
"Sa Bicol malakas ang lindol as in gumalaw yung mesa namin. I am here now at Daraga, Albay," tweeted itsmep0tp0t.
"Malakas dito sa legazpi... lasted almost a minute," bicolanodevil tweeted.
Phivolcs said the earthquake's depth was shallow at 21 kilometers.
Based on the Richter Magnitude Scale, an earthquake with magnitude 6 to 7 are "strong earthquakes" and "are accompanied by local damages near the epicenters."
Phivolcs' Earthquake Intensity scale (PEIS) describes a "strong" quake as follows:
"Generally felt by most people indoors and outdoors. Many sleeping people are awakened. Some are frightened, some run outdoors. Strong shaking and rocking felt throughout building. Hanging objects swing violently. Dining utensils clatter and clink; some are broken. Small, light and unstable objects may fall or overturn. Liquids spill from filled open containers. Standing vehicles rock noticeably. Shaking of leaves and twigs of trees are noticeable."
After the quake in Bicol region, Phivolcs also recorded a mild quake measuring at magnitude 5.2 in Batanes province at 1:43 a.m..
Four more quakes were also recorded on Friday with the strongest measured at magnitude 4.9 in Davao Oriental province.
The three other quakes were recorded near Burias Island, almost the same spot where the magnitude 6.0 was recorded.
Solidum said that the Sibuyan Sea Segment of the Philippine Fault Zone has been moving since Thursday. He said more earthquakes generated by the same fault may be felt on Saturday.
The Phivolcs chief said that since earthquakes could not be predicted, people should always be prepared for stronger tremors in the future.