Solomon Islands emergency workers have begun assessing the damage caused on Santa Cruz islands after they were hit by a tsunami on Wednesday afternoon.

Authorities say the wave has caused extensive damage to at least three villages and there are reports of casualties.

Solomon Islands Police Commissioner, John Lansley, says the tsunami has affected villages on Santa Cruz islands and people are missing.

"We understand a surge wave did affect three or four villages," Mr Lansley told Radio Australia's .

"We have some people missing and there is believe to be a few casualties. I'm hoping they will be a minimal number."

Helicopters from the Australian-led Regional Assistance Mission to Solomon Islands (RAMSI) are helping to assess the damage, emergency workers expected to arrive there tomorrow.

Pacific-wide tsunami warnings have been cancelled, but not before people on island nations across the region left for higher ground.

Traffic jams were reported in Honiara and Suva as people evacuated, while staff at the Australian High Commission in Honiara were moved to the high commissioner's residence.

Boats and ships were also moved to open water, with an ocean liner departing from the Kingdom of Tonga an hour early to avoid any potential waves.

Widespread tsunami warnings were triggered after a magnitude 8 earthquake struck just off the Santa Cruz islands at 12:12pm AEST, according to Geoscience Australia.