The US Geological Survey has reported that a magnitude-6.3 earthquake struck off Mindanao island, the southernmost major island of the Philippines.

There aren't reports yet of any major damage or injuries. The Pacific Tsunami Warning Center said it was a deep tremor, nearly 70 kilometres below the seabed, and that it's not expected to cause a tsunami.

A magnitude-6.3 quake is capable of causing severe damage, but the effects of this one are likely to be mitigated by the quake's depth and the fact that it occurred offshore.