A 6.6-magnitude aftershock has forced an aid flight to turn back on its way to Lata in the Solomon Islands, dpa reported with a link to local news.
The relief flight was carrying supplies and the Solomon's prime minister from Honiara to the worst affected areas.
The delay in aid efforts comes as officials discover the tsunami damage is much worse that originally indicated.
The shallow aftershock southeast of Kirakira follows a powerful 8.0 earthquake on Wednesday which sent a devastating tsunami over the island of Lata.
The 1-metre wall of water swept away whole villages in the flat region and killed at least nine people.
The area of destruction is much larger than first thought with up to 20 villages badly damaged or destroyed.
Television New Zealand's Barbara Dreaver was on the plane and said it was just about to land in Lata when the aftershock damaged the runway and forced it to turn back.
Prime Minister Gordon Lillo is declaring a state of emergency for the areas around Lata in the Santa Cruz area.
An aerial reconnaissance team from Australia is surveying the damage.
Authorities have not been able to assess the outlying reef islands.
There are no doctors in the disaster zone but a medical supply ship from Honiara is due to arrive Friday evening.