DAVAO CITY, Philippines—(UPDATE) Two mild earthquakes struck parts of Mindanao Tuesday morning.

A 5.1 magnitude earthquake struck off the coast of Davao Oriental province at 3:59 a.m. but it was not strong enough to cause any harm or damage to lives and property, Eleazar Jorjio, of the Philippine Volcanologist and Seismology (PHILVOCS) said.

Jorjio said the earthquake’s epicenter was traced to 62 kilometers south of Mati town. The tremor was felt at intensity 4 in Taragona, Davao Oriental, intensity 3 in Davao City, Intensity 2 in Caraga region and in Tagum City and Polomok, South Cotabato.

The cause of the temblor was tectonic, a common occurrence in the country.

The second mild quake struck at 8:39 a.m., Tuesday, with a magnitude of 5.2 and a depth of 113 kilometers, the United States Geological Survey reported. No damage was reported.

Its epicenter was traced 210 kilometers southeast of Davao city.

There was no tsunami alert issued for both quakes.

The Philippines sits on the Pacific "Ring of Fire" where continental plates collide causing frequent seismic and volcanic activity.

The worst earthquake in the country happened on August 16, 1976.

The 7.2 quake triggered a tsunami that flattened several areas in Zamboanga peninsula and Central Mindanao areas, which include the Cotabato provinces, Maguindanao, Sultan Kudarat and Sarangani.

The 1976 quake killed 5,000 to 8,000 people.

The earthquake magnitude measures the seismic energy released by the temblor while intensity is the description of an earthquake’s strength based on its observable effects on the ground.

Intensities 2 to 4 mean that people would feel slight shaking in their environment.