WASHINGTON (AFP) - A powerful 6.6 magnitude earthquake struck on Wednesday off the coast of Vanuatu in the South Pacific, but United States geologists said it was too deep to cause a tsunami.

The US Geological Survey said the quake struck at 1603 GMT about 37 kilometres west of Sola, Vanuatu.

The National Tsunami Warning Center in Palmer, Alaska said that the New Year's Day temblor, with a depth of 195 kilometres, was "located too deep within the earth" to generate a sizeable tidal wave.