Further earthquakes strike Tonga

A number of aftershocks have shaken the Pacific island nation of Tonga, following a major earthquake.

The largest of the shocks on Friday measured 6.0, compared to the 7.9 recorded in Thursday's undersea quake.

There were no reports of damage on Friday. "We haven't felt anything. Not like yesterday's big earthquake," said a hospital worker in Tonga's capital.

Thursday's quake triggered fears of a tsunami across the South Pacific, but the feared waves did not materialise.

The main aftershock on Friday struck at 0025 (1125 GMT on Thursday), 135 km (85 miles) north-east of Nuku'alofa.

Since earthquakes are calculated on a logarithmic scale, "this quake was one-tenth of the size of the big one and posed no tsunami risk," oceanographer Nathan Becker from the Pacific Tsunami Warning Center in Hawaii told the AFP news agency.

Media blamed

Thursday's earthquake, which was centred some 16km (10 miles) below the ocean floor about 160km (100 miles) north-east of the capital, Nuku'alofa, was rated as the world's strongest this year.

However police said it caused little damage to property and few injuries.

It knocked out power in Tonga - meaning the island did not receive an alert from the tsunami early warning system.

However in New Zealand hundreds of residents fled their homes in the coastal city of Gisborne after international news media reported that a tsunami could be on its way.

Auckland police had told the BBC that a tsunami was expected within 90 minutes, says the BBC's Greg Ward in New Zealand.

There has been criticism that the authorities were not quick enough to reassure people when they realised it was a false alarm.

The Minister of Civil Defence, Rick Barker, initially accepted that the official reaction was not good enough, but later blamed BBC coverage for causing unnecessary alarm, says our correspondent.