Conservationists in Africa and Asia have recorded slight increases in the numbers of one of the world's most endangered large mammals - the rhinoceros.

In Africa, it is the second year of improvement running, and, for the first time in 10 years, the number of African rhinos has risen above 11,000.

The World Wildlife Fund - hosting a conference on rhino conservation in London - said the number of rhinos in Asia is also beginning to improve.

A spokesman told the BBC that the rhino populations in India, Nepal and other parts of South Asia have risen to 2,000, thanks to successful measures to protect the animals from poachers.

In Nepal, conservationists recorded particular success story with a five-fold increase in the rhino population since the 1960s.

The recovery in numbers of African rhinos has been most marked in South Africa, but in other countries, the species continues to decline.

In Botswana and Zambia, the black Rhino is believed now to be extinct and, across a wide band of Africa, both black and white rhinos are now almost too rare to be counted.

Poachers hunt them for their horns, which are in great demand for use in Far-Eastern traditional medicine.

One conservationist said the figure showed a pleasing recovery, but a fragile one.

While the news leaves room for hope, the threat to the Asian and African rhino species remains undiminished.