A massive earthquake of 7.2 magnitude struck about 535km southeast of the South Pacific island nation of Vanuatu on Friday, the US Geological Survey said.

The quake triggered local tsunami alert although there were no initial reports of casualties or damage.

The Pacific Tsunami Warning Centre issued a warning for areas close to the quake. But the Hawaii-based centre said that there was no Pacific-wide threat of a tsunami.

The earthquake was measured at a depth of about 10km.

Initially, the quake recorded a magnitude of 7.6 but later it was downgraded.

Later the tsunami warning for coastal areas of Vanuatu, New Caledonia and Fiji, including the Fijian capital, Suva, was cancelled.

The USGS said the powerful earthquake triggered at least one aftershock with a magnitude of 5.4.