The refugees, more than 10 percent of the 350,000 residents of the tropical island chain, are living in flimsy bamboo and plastic tents in relief camps across the remote isles.

"There is some reason for scepticism. Time is a constraint but we have to try," an official, who asked not to be identified, said on Wednesday.

Authorities are working on a plan, consulting housing experts on the mainland, more than 1,200 km (745 miles) away, as well as the federal government.

Options include prefabricated fibreglass shelters or giving islanders free bamboo, timber and tin sheets to rebuild.

The islands are home to some of the world's most primitive hunter-gatherer tribes and were one of the areas worst hit by the Dec. 26 tsunami, which killed more than 15,700 people in India and more than 157,000 in total from Asia to Africa.

As they try to cope with relief operations in the islands -- where access, even for aid workers, is highly restricted -- authorities here are still recovering bodies more than two weeks after the killer waves.

Five southerly islands, with populations from 150 to 1,400, have been evacuated and authorities have yet to decide if they will be resettled or entire communities transplanted elsewhere.

"It was mind-boggling to see the devastation that has taken place," navy chief Arun Prakesh said after a tour of some of the worst-hit areas. "All human structures have been destroyed and vegetation has been swept clean from many islands."

Almost no chance remained of finding those missing and feared dead more than two weeks after the tsunami, he said.

"Knowing the sea as one does, once an object or a body is swept off, it is unlikely it will come back or be recovered."

Many of the almost 7,000 islanders dead or feared dead belong to the biggest and most advanced tribe, the 27,000-strong Nicobarese, most of whom now cram refugee camps in the capital, Port Blair, and elsewhere.

They live on straw mats under plastic sheeting and salvaged little if anything, of their possessions. Such was the rush to escape, many have no proof of their identity or that they owned their homes and land.

Other survivors are anxious for compensation so that they can rebuild as quickly as possible, before the five-month monsoon sets in.