There has been no contact with the Solomon Islands chain since Cyclone Zoe pounded the area on Sunday. Radio links are down, there are no airstrips on the islands and no ship has reached there yet.
An Australian aid crew that flew over the cyclone-hit area on Wednesday had said the islands were badly damaged but saw many residents working as normal.
But Martin Karani of the Solomons' National Disaster Management Office said aerial photographs taken from the plane showed the villages of Ravenga and Namo on Tikopia island had been virtually washed away by heavy seas.
"All that is left is the bare trunk of coconut trees with the sand halfway up the trees. There's not even any sign of the houses left," Mr Karani said
in the Solomons' capital, Honiara.
"We cannot say at this stage what happened to the 700 people living in both villages. We just hope that they were able to get out in good time."
Earlier in the day, Alan March, from Australia's aid agency AusAID, told reporters in Canberra that the Australian crew had reported widespread damage to traditional housing, crops and gardens on two islands in the remote Santa Cruz chain.
"But there is no evidence albeit from 500 feet of injuries or casualties," Mr March said A dispute with the crew of a Solomons patrol boat over unpaid wages has blocked the departure of a vessel carrying emergency supplies to the islands, which are at the furthest reach of the sprawling Solomons archipelago.
But March said that authorities in the impoverished south Pacific country had chartered a commercial passenger vessel that was due to leave
Honiara at midnight yesterday.
The boat will carry enough water, food and medical supplies for up to 700 families and a medical team but the journey was expected take two or three days depending on the weather.
Mr March said two islands, Tikopia and Anuta, bore the brunt of the storm, with wind damage to three other islands, located 600 miles southeast of Honiara and about 1,800 miles northeast of Australia.