Sydney - A 6.3-magnitude earthquake hit near the South Pacific archipelago of Tonga on Wednesday but there were no immediate reports of damage or casualties, the US Geological Survey said.

The quake hit at 09:11 GMT and was centred 256 kilometres (159 miles) northeast of the Tongan town of Neiafu at a depth of 74 kilometres, the USGS said.

The Pacific Tsunami Warning Centre in Hawaii did not issue a tsunami alert.

The quake occurred near fault lines in the Pacific "Ring of Fire" where continental plates in the earth's crust meet and earthquakes and volcanic activity are common. - Sapa-AFP