The World Health Organisation says it has been notified by Japan of a new variant of the coronavirus discovered there.
Japan's health ministry said on Sunday it had detected a new coronavirus variant in four travellers from Brazil's Amazonas state.
The variant featured 12 mutations, including one also found in highly infections variants discovered in the United Kingdom and South Africa.
The Japanese health ministry had earlier said it was working with other countries and medical experts to analyse the variant.
The previously identified variants from the UK and South Africa are more contagious but the behaviour of this new variant and the illness it causes are not yet known.