Aug 3 (Reuters) - An earthquake of magnitude 6.7 struck off the eastern shore of the island of Mindanao in the Philippines on Saturday, the German Research Centre for Geosciences (GFZ) said.

The quake was at a depth of 10 km (6.21 miles), GFZ said.

The U.S. Geological Survey said pegged the magnitude at 6.8.

The U.S. National Tsunami Warning Center said that there was no tsunami threat from the earthquake.

Philippine seismology agency PHIVOLCS said in an advisory it was not expecting damage from the offshore quake, but warned of aftershocks.

The Philippines is in the Pacific "Ring of Fire," where volcanic activity and earthquakes are common.