6.8 magnitude earthquake strikes off Rabaul in Papua New Guinea
Geophysicist talks on the phone concerning the earthquake. Reuters

Three powerful earthquakes ranging in magnitude from 5.0 to 5.9 struck the Philippines main island Luzon on Saturday, the U.S. Geological Survey (USGS) said. The USGS said the quakes occurred about 90 kms (55 miles) south of the capital Manila occurred over a period of about 20 minutes, sending people running out of buildings.

There were no immediate reports of damage or casualties from the quakes, the strongest of which hit the coast close to the town of Mabini, south of Manila.

According to US Geologists, the first 5.7 magnitude quake struck inland at 3:08 pm (0708 GMT) followed by the 5.9 quake just a minute later. The authorities say their epicenters were within a distance of a few kilometers from each other. The 5.0 quake hit the same region after another 20 minutes.

AFP reported that people were seen running out of office buildings in Manila's financial district due to the tremor. The local television network, ABS-CBN broadcast live footage of frightened commuters, who were fleeing the passenger terminal at the port of Batangas, near the epicenters.

The channel also quoted a few local officials saying that the quakes broke the windows of some houses in the region. The region has experienced several tremors since earlier this week.

The Philippines sits on the highly seismically active zone "Pacific Ring of Fire" where many continental plates on the earth's crust keep colliding. Hence, it experiences frequent earthquakes.

The last lethal earthquake to hit the country before the February 10 quake was a 7.1-magnitude tremor that left over 220 people dead and destroyed historic churches when it struck the central islands in October 2013.