APIA (AFP) – A powerful earthquake with a magnitude of 8.0 struck off the South Pacific island nation of Samoa on Tuesday, wiping out villages and killing 19 people in the region, reports said.

At least 14 people were reported to have died in American Samoa, and five in Samoa as enormous waves battered the island states, with one witness saying the wall of water had been up to 30 feet (nine metres) high.

[O]ne local journalist told AFP entire villages had been wiped out in Samoa on the worst-hit south and southwest coasts in an area where thousands of people live. The Samoan capital of Apia was evacuated as authorities scrambled to get thousands of people to higher ground.

Witnesses said cars were swept out to sea in American Samoa where buildings were destroyed in what the US congressman for the territory said was a scene of "devastation."

The US Geological Survey said an 8.0-magnitude quake struck at 6:48 am (1748 GMT) at a depth of 18 kilometres (11 miles), 195 kilometres south of the Samoan capital Apia.

[T]he centre said waves of up to 1.57 metres (over five feet) above the average sea level had smashed into American Samoa.

Eyewitnesses said the waves were much larger.

["They] said five tsunami waves have hit the park visitor centre in Pago Pago. It would appear park offices and the visitor centre there have been destroyed. "One of the waves was about 30 feet high."

Samoan journalist Jona Tuiletufuga told AFP there was widespread destruction with possibly thousands of people left homeless on the island.

"We are getting reports of missing people in areas were damage is extensive on the south and southeast coasts," he told AFP. "Entire villages have been wiped out."

Tuiletufuga said there were up to 70 villages in the worst-hit area and each housed from 300-800 people.

A New Zealand tourist who called Radio New Zealand to appeal for help said he was looking over an area of destruction from high ground near Apia.

"We clambered up a hill and one of the party has a broken leg. We just need help. There will be people in a great lot of need around here, it's flattened." Information from both islands was patchy.

American Samoan radio station KSBS-FM said at least 14 people had been killed by the quake and resulting tsunami.

New Zealand deputy high commissioner to Apia, David Dolphin, said five people were reported to have died on the island.

Most of the damage appeared to be centred on southern coast where waves of six to eight metres were recorded, he said.

"There are reports of some quite serious damage, at least five fatalities and quite a few reports of people missing," said Dolphin, who was on the north coast at the time.

[A] series of powerful aftershocks rattled the South Pacific in the hours after the initial quake.

The Pacific Tsunami Warning Centre initially issued a tsunami warning for a large area of the South Pacific including Fiji, New Zealand and Tonga.

The USGS said the 8.0-magnitude quake struck at a depth of 18 kilometres.

Several of the Earth's tectonic plates meet in South Pacific and violent geological activity is common.

Large quakes with an under-ocean epicentre can trigger tsunamis that can have devastating effects.

In December 2004 an undersea earthquake off Indonesia's Sumatra set off a tsunami that killed more than 220,000 people around the Indian Ocean and laid waste to huge areas of coastline.