An earthquake measuring 7.1 on the Richter scale the island of Mindanao in Philippines on Saturday morning, the US Geological Survey (USGS) said.

The quake struck offshore near Glan town in Sarangani province at a depth of 10 km around 4.23 a.m., 68 km south of the city of General Santos, Xinhua news agency quoted the USGS as saying.

Philippine Institute of Volcanology and Seismology chief Renato Solidum said that residents near coastal areas in the region should be wary of possible tsunami waves.

However, no tsunami warning was raised after the quake.

There were no immediate reports of injuries or casualties.