(REUTERS) - A 5.6-magnitude earthquake struck the center of Mindanao island in the Philippines on Wednesday (April 12), the US Geological Survey said.

The quake, initially reported as a magnitude 6.0, struck at 5.21am on Wednesday (5.21am Singapore time).

It was very shallow, at a depth of 6km, which would have amplified its effect. Its epicentre was 5.5km north-east of Cotabato on the large southern island of Mindanao.

A magnitude 5.6 quake is considered moderate and is capable of causing considerable damage.