A tsunami threat to Fiji has been cancelled, shortly after a powerful earthquake struck off the South Pacific island nation, prompting many panicked coastal residents to evacuate to higher ground, the Pacific Tsunami Warning Centre says.
The quake, which hit at 10.52am (2152 GMT Tuesday), was centred 280 km southwest of Fiji's capital, Suva, at a shallow depth of about 15km, the US Geological Survey said.
It was originally recorded with a magnitude of 7.2 but was later downgraded to 6.9.
There were no initial reports of widespread casualties or damage.
Fiji's national disaster office issued a nationwide tsunami warning after the powerful underwater quake, leading to widespread evacuations and traffic jams.
"The earthquake caused a fair bit of panic; there are cars lined up trying to get to higher ground," Jovesa Saladoka, the Fiji director of Oxfam, told Reuters by telephone from Suva.
Corrine Ambler, a Red Cross worker in Suva, said on Twitter all Red Cross staff and most of the capital was "headed to higher ground".
At least two aftershocks with magnitudes of more than 5 rattled Fiji soon after the quake.
The Pacific Tsunami Warning Centre cancelled the tsunami threat to Fiji just over an hour after the first tremor.
There was no threat to nearby Pacific island nations Vanuatu and New Caledonia, authorities said.
'Crazy' scenes in Suva
An Australian tourist says things got a bit "crazy" in Fiji's capital Suva after a powerful earthquake struck south of the islands.
Sydneysider Dan Bennett was near the pool of his waterfront hotel in Suva at the time but did not feel any tremor.
He was told by staff to pack up and prepare to evacuate.
"Everything outside is pretty crazy - there's sirens going off and there's cops everywhere," he told AAP.
"I didn't feel the quake. I was just reading about it on Twitter and then sirens started going off."
A number of people reported on social media feeling the quake, from Suva to Nadi, and Sigatoka on the main island's southern coast.
Pictures were posted of locals and holidaymakers moving to higher ground.
Local Kelvin Anthony's office in Suva was briefly evacuated but workers were allowed to return shortly after.
"It was an hour 30 minutes of rush and then we are back in office. Sipping coffee. Eating cake. Hustling," he tweeted.
At least three aftershocks have been recorded nearby, according to Geoscience Australia.
