Manila, Philippines: Officials say a strong earthquake has shaken parts of the southern and central Philippines, frightening people but causing no serious damage or injuries.

The U.S. Geological Survey said the magnitude-6.1 earthquake struck Monday afternoon at a depth of 38 kilometres (23 miles).

Government seismologist Jane Punongbayan said it was centered 205 kilometres (127 miles) northwest of Zamboanga city and was too deep and far from urban areas to cause any damage or injuries. She said aftershocks were expected.

Zamboanga city police director Angelito Casimiro said people attending Mass at a Roman Catholic shrine exchanged glances when the ground began to shake mildly, but the ceremony proceeded after the shaking stopped.

The Philippine archipelago lies in the Pacific "Ring of Fire," where earthquakes and volcanic activities are common.