Health officials in Britain have identified six cases of a highly contagious coronavirus strain first identified in the Brazilian city of Manaus -- including one in a person who has not been traced.

Scientists say the variant is more transmissible and may be more resistant to existing vaccines than the original virus, and may be able to infect people who have previously had COVID-19.

Direct flights from Brazil to the U.K. have been halted, but the newly identified cases have been linked to people who came to the U.K. from Brazil through other European cities in early February.

The arrivals came days before the U.K. imposed a 10-day hotel quarantine on people arriving from high-risk countries, including Brazil.

Three of the cases of the variant are in Scotland and two in southwest England. The sixth individual has not been identified because they did not correctly fill in a form with their contact details. Public Health England said it was working to find the person and is conducting local mass testing to see whether the variant has spread in the community.