A LARGE-SCALE relief effort will be launched today to deliver aid to thousands of Solomon Islanders left homeless after a tsunami in the Pacific nation left hundreds missing when it washed away entire villages.

At least 15 people were last night confirmed dead after 10m waves struck some of the Solomons' most remote western provinces early yesterday, sending a wall of water 500m inland.

The tsunami was triggered by a 8.1-magnitude undersea earthquake at 6.40am (AEST) about 350km of the capital of Honiara.

An Australian Government team comprising ministerial officials and the Red Cross was yesterday sent to begin the rescue effort at Munda in the Western Province. The major rescue effort was beginning last night with food and medical supplies loaded on to ships in Honiara.

Solomon Islands Prime Minister Manasseh Sogavare said last night the death toll was expected to rise.

But it could have been worse if the giant waves had come at night.

"We are lucky that it happened during the daytime - that the people observed that the sea receded and that basically is a sign that something is not right and then most people have taken to higher grounds," he said.

"Those that have been unfortunate to lose their lives were those people who were not aware of what is happening."

Mr Sogavare said the full extent of casualties and damage was still unclear. "Most of the islands are low-lying and the extent of the damage is yet to be known," he said.

Buildings were levelled by the earthquake, which created a series of large waves that continued to lash the Pacific Ocean islands for several hours and washed away entire coastal villages. The Solomon Islands Government last night issued a warning to expect more tsunami activity following advice by Australian seismologists that another big earthquake was possible in coming weeks.

The quake was one of the biggest in the Pacific Rim since the Boxing Day quake off Indonesia in 2004, which unleashed massive tsunamis that killed more than 200,000 people across the Indian Ocean.

An initial alert from the Pacific Tsunami Warning Centre in Hawaii to Australia yesterday caused widespread panic in north Queensland, where traffic was gridlocked out of Cairns after radio broadcasts told people to immediately evacuate the coast.

The confusion continued further down the coast, with ferry services on Sydney Harbour being halted and surfers on Bondi Beach asked to leave the water and the beach in preparation for giant seas.

Queensland Premier Peter Beattie was highly critical of the early warning systems, and telephoned John Howard to get accurate information on the extent of the threat. "Frankly, we need warning systems out to sea on islands nearby to give us a better indication," he said.

"We were trying to work out the magnitude of it but we were shooting blind, and I don't believe this is good enough for Australia."

Solomon Islands government spokesman Alfred Maesulia last night conceded the death toll was likely to "rise significantly", with a full assessment of the destruction hindered by the isolation of the hardest-hit areas of the Choiseul province, on the maritime border of Papua New Guinea, and Western province, where the tourist town of Gizo was completely submerged by water.

Mr Maesulia said he feared disease outbreaks and untreated injury could "worsen the situation", particularly in the more isolated coastal communities.

"The number of deaths and injuries are continuing to rise, and will rise significantly as we make contact with these remote communities. It could be in the hundreds that are missing, entire villages have been wiped out, we don't know how bad it is."

The Australian Government pledged $2 million last night in initial emergency and reconstruction assistance.

The Australian-led Regional Assistance Mission to Solomon Islands, deployed to the strife-torn nation in 2003, was being mobilised under the direction of the Solomons Government.

Thousands of locals who escaped to higher ground ahead of the waves slept in bushland without sanitation or shelter.

A Royal Solomon Islands Police spokesman said there was great uncertainty about the extent of the damage, particularly in Choiseul.

"The southern end of Choiseul is the great unknown at this stage. There are so many communities that are out of touch and we don't know what happened," he said.

Officials are not expected to reach the devastated areas until early this afternoon.

Australian dive shop owner Danny Kennedy said the wave that hit Gizo was 3m high.

"There are boats in the middle of the road, buildings have completely collapsed and fallen down," he said. "We're just trying to mobilise food and shelter for people at the moment because in the town alone there's going to be 2000 to 3000 homeless."

The lessons of the 2004 Boxing Day tsunami, which hit 13 countries across the Indian Ocean, appear to have saved hundreds of lives. Solomon Islands' Red Cross Secretary-General Charles Keli said the "tell-tale" signs of the ocean receding from the shore, following a series of 2m waves, sent people running. A government warning, broadcast about 30 minutes after the earthquake, also gave notice of the imminent danger.

"The waters were moving back into ocean and a lot of people in these areas evacuated themselves to higher ground," he said.

The Australian Government said it was not aware of any Australian casualties.

Mr Sogavare called on leaders at all levels to ensure victims received all the help they needed.