A magnitude 7.1 earthquake occurred off the Solomon Islands on Friday sending villagers fleeing to higher ground.
A magnitude 8.0 quake and tsunami killed 13 people on Wednesday. The toll is expected to rise.
The latest quake was at a depth of 9km, 23km from the main town, Lata. It was the latest in a series of aftershocks on Ndende island in the eastern Solomons where 20 villages were inundated.
The area was officially declared a disaster zone on Friday, as Australian Foreign Minister Bob Carr announced $A300,000 in relief payments and said a Royal Australian Air Force Hercules had been sent to provide logistical support.
An estimated 6000 people are homeless.
Patients in a hospital were taken to higher ground on Friday night. Temotu Province disaster chairman Solomon Palusi said most people had already moved to higher ground.
But a decision was made to move patients from the hospital in Lata, the provincial capital on Santa Cruz Island, to higher ground after the second big quake.
World Vision flight
World Vision says it has been able to survey remote villages that have been isolated since the earthquake and tsunami and they appear to have fared well.
There had been fears of widespread destruction because many of the villages are on low lying islands in the Santa Cruz group, 600km from the capital Honiara.
Solomon Islands programme director Andrew Catford said there was a flight over the islands on Friday and it appeared, from the air, that there is no major damage.
He said that means aid relief can concentrate on the villages around Lata where the quake was centred.