A powerful earthquake in the southern Philippines has killed at least eight people and injured several others.

The tremor, registering 6.8 on the Richter scale, struck the island of Mindanao in the early morning.

Two of those killed were crushed by collapsing buildings.

Police say about 30 houses collapsed and the quake caused a landslide and a tidal wave in the nearby island of Sarangani forcing hundreds of people to flee the affected areas.

The quake knocked out electric power in several cities around the Rio Grande river basin about 1,000-kilometres south of Manila.

Wednesday's tremor is the strongest to hit Philippines in a decade since the earthquake on the main island of Luzon which killed more than 1,500 people in 1990.

From the newsroom of the BBC World Service