Relief supplies began trickling into tsunami-hit communities in the Solomons Islands Monday, as another powerful aftershock rattled the Pacific nation in the wake of last week's 8.0-magnitude earthquake.

The aftershocks had slowed but not halted aid operations in the remote Santa Cruz islands, where at least 10 people died in the tsunami triggered by the quake last Wednesday, the Red Cross said.

"The wharf in (regional capital) Lata has been damaged, so it can't take large, heavy trucks," Red Cross secretary general for the Solomon Islands, Joanne Zoleveke, told AFP.

"But we feel like we've got logistics down on the ground now, and distribution is becoming more orderly. Water, shelter and food are the major issues."

The latest jolt on Monday morning measured 6.3 and was centred 51 kilometres (32 miles) southwest of Lata at a depth of 35 kilometres (21.7 miles), according to the US Geological Survey.

It was the third tremor to top 6.0 since Friday but Zoleveke said the seismic rumblings had not halted the emergency operation.

"They're sort of getting used to it now. They feel that they're coping with the aftershocks, even though some of them are quite big," she said.

The Solomon Islands government has declared the Santa Cruz Islands a disaster area. Aerial surveys indicate most of the damage is confined to the Lata region.

Almost 600 houses are believed to have been destroyed, with most of the destruction caused in the initial earthquake and the metre-high tsunami which swept through coastal areas soon after, leaving more than 3,000 people homeless.

Australia and New Zealand have both pledged funds to the relief effort, with Australia also sending an air force Hercules to survey the disaster zone and chartering a flight to ferry injured patients to the capital Honiara.

A New Zealand Air Force Boeing 757 departed for Honiara on Monday carrying sanitation kits, tarpaulins, water containers and chainsaws packs.

The Solomons are part of the "Ring of Fire", a zone of tectonic activity around the Pacific that is subject to frequent earthquakes and volcanic eruptions.

In 2007 a tsunami following an 8.0-magnitude earthquake killed at least 52 people in the Solomons and left thousands homeless.