A powerful 8.0 magnitude earthquake set off a tsunami that killed at least five people in a remote part of the Solomon Islands.

It also triggered evacuations across the South Pacific as island nations issued tsunami alerts.

The quake struck 340km east of Kira Kira in the Solomons, the Pacific Tsunami Warning Center in Hawaii said.

It issued warnings for the Solomons and other South Pacific nations, including Australia and New Zealand.

It later cancelled the warnings for the outlying regions.

A tsunami measuring 90cm hit near the town of Lata on the remote Santa Cruz island, swamping some villages and the town's main airport as people fled to safety on higher ground.

More than three dozen aftershocks up to magnitude 6.6 rocked the region in the hours after the quake, the US Geological Survey said.

Lata hospital's director of nursing, Augustine Pilve, told New Zealand television that five people were killed, including a ten-year-old boy.

He said that more casualties are possible as officials make their way to at least three villages that may have been hit.

"It's more likely that other villages along the coast of Santa Cruz may be affected," he said.

Disaster officials in the Solomon Islands capital Honiara told the Solomon Islands Broadcasting Corporation that they believed six people were dead and that five villages had suffered damage.

Solomon Islands Police Commissioner John Lansley said it was too early to fully assess the damage or casualty numbers.

He said authorities hoped to send aircraft to the region tomorrow to help determine the extent of the damage.