London: The first monkeys cloned in the same way as Dolly the sheep have been born, raising concerns that it may soon be possible to clone humans.

Chinese scientists at the Chinese Academy of Sciences on Wednesday announced the births of Zhong Zhong and Hua Hua, a pair of healthy macaques that are genetically identical.

The infants are being bottle fed and are said to be growing normally compared with monkeys their age. More cloned births are expected this year.

Previously scientists have "cloned" primates by splitting an embryo in half, but the process is essentially just artificial twinning rather than true cloning.