© ReutersWreckage left behind in the village of Leone in American Samoa
Scores of people are feared dead and many more injured after a powerful earthquake triggered a tsunami that swept the Pacific islands.

Cars and people were swept out to sea by the fast-churning water as survivors on the worst-hit islands of Samoa and American Samoa fled to high ground, where they remained huddled for hours.

The floodwater engulfed cars and homes, flattened villages and washed ashore a large boat that came to rest on the edge of a highway.

The 8.3-magnitude quake struck about 125 miles from Samoa at 6.48pm BST, sending a large wave into Apia, the capital of Samoa, and a 1.5-metre wave into Pago Pago, the capital of American Samoa.

At least 99 people are feared dead after villages were destroyed by the waves, with a two-year-old British child among those confirmed dead.

The Samoan police commissioner, Lilo Maiava, said police there had confirmed 63 deaths, but said that with officials still searching affected areas that number could rise soon.

Officials in American Samoa said at least 19 people were killed on the island. Unconfirmed reports said five people were dead in Tonga.

One agency reporter said there were "bodies everywhere" in the main hospital on the Samoan island of Upolu, including at least one child. She said three or four villages had been wiped out on a popular tourist coast near Lalomanu, on the south of the island.

© Fili Sagapolutele/APWater swamps a main road in the downtown area of Fagatogo in American Samoa
Hampered by lack of power and communications, officials struggled to assess the casualties and damage. But the death toll seemed sure to rise.

The Samoan prime minister, Tuilaepa Sailele Malielegaoi, looked shaken aboard a flight from Auckland, New Zealand, to the Samoan capital.

"So much has gone. So many people are gone," he told reporters. "I'm so shocked, so saddened by all the loss."

Malielegaoi said his own village of Lepa was destroyed.

"Thankfully, the alarm sounded on the radio and gave people time to climb to higher ground," he said. "But not everyone escaped."

In Washington, Barack Obama declared the situation a disaster, making federal funds available to victims in American Samoa - a US territory of about 65,000 people.

A US coastguard spokesman, Lieutenant John Titchen, said a C130 plane was being dispatched to deliver aid to American Samoa, assess damage and take the governor home.

In Samoa, the wave reportedly sent water and debris surging up to 100 metres inland, leaving terrified residents fleeing their homes for higher ground.

In Apia, on Samoa's second-largest island, witnesses said the ground shook for up to three minutes. Businesses and schools were forced to close and the city was left virtually deserted with thousands of people gathered on nearby hills, according to reports. Villagers reported cars and houses washed out on to reefs.

Graeme Ansell, a New Zealander who was at the beach village of Sau Sau Beach Fale on Samoa, said it was levelled by the wave. "It was very quick. The whole village has been wiped out," Ansell told a New Zealand radio station from a hill near Apia. "There's not a building standing. We've all clambered up hills, and one of our party has a broken leg. There will be people in a great lot of need round here."

© ReutersAn overturned vehicle is stranded among wreckage in Si'umu
American Samoa is home to a US national park that appears to be especially hard-hit. Holly Bundock, spokeswoman for the national park service's Pacific west region in Oakland, California, said the park superintendent and another member of staff had located only a fifth of the park's 13 to 15 employees and 30 to 50 volunteers.

The territory is believed to have been hit by four separate waves. In Leone, one of many villages flattened, hundreds of people fled their homes for higher ground.

Minutes later their homes were gone, crushed by the force of the wave.

"It's just devastating like the wrath of God," said Vincent Iuli, a villager. "I've never seen anything as powerful as this. I was just about to get into the car to go to work when the warning came on the radio."

Iuli raced to take his wife and children to higher ground but got split up in the confusion. The wave hit the village 15 minutes later.

Hundreds sought shelter in a church on higher ground. While the wave rushed past the building the water seeped in and reached the top of the pews where many were standing. Six people were killed and another three were missing. After two hours of frantic calls Iuli made contact with his wife.

"There's a lot of mud and there are dead fish lying everywhere for about a quarter of a mile inland."

Hundreds of people are crowding on the high ground behind the village where chiefs have set up a camp until emergency services reach them. "Each family has a chief and this is when they rise to the occasion," Iuli said.

Mike Reynolds, the superintendent of the national park of American Samoa, was quoted as saying four tsunami waves from 15ft to 20ft high roared ashore soon afterwards, reaching up to a mile inland.

In Tonga, New Zealand's acting prime minister, Bill English, said the situation could "look worse rather than better" over the next 12 hours.

"There are a considerable number of people who've been swept out to sea and are unaccounted for," English said.

"We don't have information about the full impact and we do have some real concern that over the next 12 hours the picture could look worse rather than better."

The Pacific tsunami warning centre said it had issued a general alert for the region, which includes the Cook Islands, New Zealand, and Hawaii, and was monitoring the situation.

© ReutersThe Sinalei resort in Samoa after it was struck by a tsunami
Hawaii, which was initially put on tsunami alert, was later downgraded.

Japan's meteorological agency issued a tsunami warning along its eastern coast.

The US geological service said the earthquake struck about 20 miles below the ocean floor and was followed 20 minutes later by an aftershock of magnitude 5.6.

Brian Atwater, a tsunami expert for the service, said although the earthquake and tsunami were big, the 2004 Boxing Day tsunami, which killed 150,000 people, was 10 times as strong.

Samoa and American Samoa have a combined population of about 250,000.