SYDNEY—A powerful earthquake in the South Pacific triggered a tsunami that destroyed villages and killed at least five people in the Solomon Islands Wednesday, according to government and hospital officials.

A wave measuring three feet reached the island chain after the quake hit around midday local time, the Pacific Tsunami Warning Center said. The magnitude-8 quake, with a depth of 17.8 miles (28.7 kilometers), was centered about 220 miles east of the Santa Cruz Islands, part of the Solomon Islands nation, according to a...