AUCKLAND, New Zealand — A powerful 8.0 magnitude earthquake caused a tsunami that sent strong waves crashing into several South Pacific islands, with officials in the Solomon Islands fearful that some residents had lost their lives.

The earthquake prompted tsunami warnings and watches from several island chains to Australia and later New Zealand, but many of those were later canceled.

The low-lying Solomon Islands, however, were not spared. George Herming, a government spokesman, said the tsunami sent two nearly five-foot waves into the western side of Santa Cruz Island, damaging at least 50 homes.

The police commissioner of the islands, John Lansley, said his patrols reported that said that at least four people and perhaps more were likely killed by the waves and ensuing flooding.