A strong earthquake measuring 8.0 has rocked the Pacific island nation of Tonga, but initial fears that it might trigger a tsunami have receded.
The US Geological Survey said the quake was centred some 16km (10 miles) below the ocean floor about 160km (100 miles) north-east of the capital, Nuku'alofa.
It struck at 0426 local time (1526 GMT), the USGS said. There were no reports of damage or injuries.
Tsunami alerts were issued across the region but were cancelled within hours.
The earthquake was rated as the strongest of 2006.
Experts at the Pacific Tsunami Warning Center, based in Hawaii, revised initial estimates that a destructive wave could hit Tonga, Fiji, New Zealand, Samoa or Hawaii.
Sea level readings suggested that a small tsunami was generated, and authorities near the epicentre were warned to be on guard for rough seas.
But warnings of more serious waves were cancelled less than two hours after the quake struck.
Early estimates had suggested that Fiji could bear the brunt of any large tsunami.
Areas along New Zealand's coastline were also placed on high alert, although concerns eased as warnings were scaled down.
Experts say earthquakes as strong as magnitude 8.0 could trigger a lethal tsunami, depending on conditions and the nature of the quake.
Initial reports from police in Tonga suggested the quake caused little damage to property and few injuries.
The owner of Tonga Radio, Ron Vea, told the BBC about the moment the earthquake struck.
The quake caused damage but it is not thought too serious
"I was asleep and we are in an apartment building, two-storey apartment building, just across from the waterfront and then we felt the crackling sound, it's just a weird kind of a sound I haven't heard before.
"When I got up I felt the building swaying back and forth and it was for at least a minute that it went on like that."
Reports from the capital, Nuku'alofa, suggested heavy shaking and some potential damage to property. Other islands reported lesser shocks.
The previous biggest earthquakes in the Tonga region of the Pacific were a magnitude 6.7 in January 2004 and a 7.2 in January 2000.