India's military is building emergency helicopter landing pads in the remote Andaman and Nicobar Islands to speed up relief efforts following the tsunami.

The authorities say all inhabited islands have been visited

Officials say the priority is faster delivery of food, water and medicine to Katchall island, where almost 5,000 people are dead or missing.

But the remoteness of many islands is slowing the relief operation, and hopes of finding survivors are fading.

India's death toll is 9,691, with most of those confirmed dead in Tamil Nadu.

The BBC's Jonathan Charles in the Andaman Islands says that tsunami survivors in remote areas - which take days to reach by sea - cannot wait long for help.

We cannot give up hope and our boys are still scouring the jungles Vice Admiral Raman Puri

Two-thirds of the population in Katchall island - which lies close to the epicentre of the 26 December earthquake off the Indonesian island of Sumatra - are either dead or missing.

Those who survived are now living in the open, after their homes were destroyed.

The Indian military says that more than 6,000 people are still missing throughout the Andaman and Nicobar archipelago. More than 900 are known to have died.

'Speedy' response

"We will continue to search until the slightest hope. But 98% of all the survivors, we believe we have got them with us," Vice Admiral Raman Puri told reporters in the islands' capital, Port Blair, where many survivors are in refugee camps.

India's response to the disaster was extremely prompt Foreign Secretary Shyam Saran

"All inhabited islands have been visited. There is nothing that has not been visited.

"We cannot give up hope and our boys are still scouring the jungles but we will call off the search after a week," he said.

The Indian government, which has been reluctant to seek international help, says its relief and rescue operation has been effective.

"India's response to the disaster was extremely prompt," said Foreign Secretary Shyam Saran.

"We are confident that we have the capabilities and resources to overcome it."

Many survivors are in camps in Port Blair

The authorities have been criticised for not allowing foreign aid organisations into the Andamans.

On Wednesday, however, it was announced that the UN children's fund Unicef had been granted access to vaccinate against measles in refugee camps.

"We started in Port Blair... and we will continue also to the other islands from this afternoon upon request of the government," Dr Marzio Babille, chief of health for Unicef in India told the Associated Press.

Eaten away

Officials say Katchall was swept several times by the giant waves on 26 December.

More than half the island is still submerged, and geologists fear much of it may have been eaten away by the sea.

ANDAMAN AND NICOBAR About 400 islands, 38 inhabited Islands are peaks of submerged mountain range Indian territory, area of 8,249 sq km Population around 370,000, about 100,000 in Port Blair Number of tribes, including Jarawas, Onges and Shompens

The authorities say 3,912 people have been rescued from Katchall. About 60% of the island's pre-disaster population were aboriginals.

Hundreds of Indian border guards have been flown in to help the navy and police search for those missing.

India's authorities say a missing person will not be officially listed as dead unless their body is found - preventing or delaying compensation pay-outs.

The islands are home to a number of tribes, some of whom have had little or no contact with the outside world.

There was anger on Wednesday after India's Supreme Court lifted a ban on tree-felling on the islands to help rebuilding efforts.

Environmentalists say the six-month lifting of the ban will encourage loggers and others to destroy forests which cover more than 80% of the archipelago.

India's Zoological Survey also plans a detailed survey to determine the extent of any damage to coral reefs.