UPDATED 12.56pm An earthquake originally estimated at magnitude 7.2 but now rated as 6.9 struck 284 kilometres off the coast of Fiji at 10.52, the U.S. Geological Survey said.

The National Weather service Pacific Tsunami Warning Center, said the quake occurred south of Fiji.

"Based on the preliminary earthquake parameters, hazardous tsunami waves are possible for coasts located within 300km of the earthquake epicenter.''

People living on coastal areas were being warned to stay alert for any information and to follow instructions from national and local authorities.

A second notice put out by the Pacific Tsunami Warning Center just after 11.30m NZT said tsunami waves reaching 0.3 to 1m above the tide level were possible for some coasts of Fiji.

"For all other areas covered by this product...no tsunami threat is expected.''

There is no tsunami threat for New Zealand, Civil Defence says.

The Ministry of Foreign Affairs and Trade is telling New Zealanders in Fiji to follow the advice of local authorities.

A spokesperson for MFAT said 185 New Zealanders are registered as being in Fiji.

It's sent a message to all of them advising they follow any evacuation instructions and keep family in New Zealand informed of their well being.

The Pacific Tsunami Warning Centre says any tsunami threat from this earthquake has now passed.

Avinesh Jobal, chief of staff at the Fiji Times, said reporters had been getting calls from people on Fiji's west coast saying they'd felt the quake.

No reports of injuries or major damage had been reported. he said.

Staff in his office, based in Fiji's capital, Suva, had not felt the quake.

Fiji Sun staffer Rosi Doviver told the Herald her office in Suva felt the quake.

"We were just looking at each other, watching everything shake. It wasn't too bad, just water bottles and tables  shaking)."

Another staffer, Tamanilo, said: "The tables were shaking but it was pretty mild. Not like the ones you watch [on TV], like the Japanese one, not as bad as Christchurch.

"We haven't had any reports of damage. We are still monitoring."