A magnitude-5.8 quake was been reported in the area south-west of Samoa.
The U.S Geological Survey reported that the epicentre of the earthquake was just shy of 200 km southwest of Apia - the capital and largest city of Samoa. It hit at a depth of 29.8km.
There were no immediate reports of any damage or casualties.
The Pacific Tsunami warning Center, based in Hawaii, tweeted that there was no tsunami threat from the earthquake: