Two earthquakes measuring between 7.6 and 9 on the Richter scale caused a tsunami some 10 meters (30 feet) high that completely flooded the towns of Gizo and Noro. The official death toll has already reached 32, and scores of villagers are reported missing.
Arnold Moveni, the head of the local emergency relief committee, said rescuers have conducted flights over the hardest-hit areas, and that the death toll is likely to keep rising as reports come in from other affected areas.
Meanwhile, leading seismologists fear a new quake, comparable to Monday's tsunami, may shake the islands, and are almost sure that slight tremors will continue. The most powerful quakes on Monday were centered on an area about 350 km northwest of Honiara, the capital of the island group.
Kevin McCue, director of the Australian Seismological Centre, said quakes of a magnitude of up to 7.5 were likely to continue west of the Solomon Islands in the next few days.
"This region typically has double earthquakes - [there have been] six sets of them since 1907," he told Australian radio.
With a population of about 550,000 people the island group is a popular venue with tourists, and local residents rely mainly on fishing and tourism for income.
The most powerful and disastrous calamity involving a tsunami over the last 40 years occurred in December 2004, when an earthquake measuring 9 on the Richter scale in the Indian Ocean generated a tsunami that hit South Asian countries, particularly Indonesia, killing more than 280,000 people. Tens of thousands were reported missing.