The tribes living in the Andaman and Nicobar group of islands are Jarawas, Shompens, Sentinelese, Onges, Andamanese and Nicobarese, all of whom are considered the modern world's remaining links with the primitive civilisation.

The fate of the 100-strong Shompens in Campbell Bay, which is closest to the epicentre of last Sunday's massive undersea earthquake, and the Sentinelese, inhabitants of North Sentinel Island, is not known, according to a spokesman of Indian Tribal Affairs Ministry.

The Sentinelese are still out of reach to people from outside world.

All bridges to the areas inhabited by Shompens and Sentinelese have been washed away and the authorities are relying only on boats to make survey of the places to ascertain their fate.

Efforts are on to trace the 100-odd Onges who live in Dugon Creek.

The Nicobarese, economically the most prosperous of the tribes of Andaman and Nicobar, are the hardest hit by the tsunamis and most of the 26,000-strong community are feared to have perished.

The Jarawas, one of the six aboriginal tribes to have survived since the Mesolithic period dating back to 2,000 years and who live in the middle of Andaman, are unlikely to be affected much because they are in hilly terrain. The Andamanese live in a bigger landmass, the Strait Island.

A team of anthropologists from Kolkata has been dispatched to the Andaman and Nicobar islands to make an assessment of the damage caused to the tribes by the giant tidal waves.