Authorities in Vietnam have detected a new coronavirus variant that is a combination of the Indian and UK COVID-19 variants and spreads quickly by air, the health minister said on Saturday.

After successfully containing the virus for most of last year, Vietnam is grappling with a spike in infections since late April that accounts for more than half of the total 6,713 registered cases. So far, there have been 47 deaths.

“Vietnam has uncovered a new COVID-19 variant combining characteristics of the two existing variants first found in India and the UK,” Health Minister Nguyen Thanh Long said in a statement.

“The new variant is very dangerous,” he added.

The Southeast Asian country had previously detected seven virus variants: B.1.222, B.1.619, D614G, B.1.1.7 – known as the UK variant, B.1.351, A.23.1 and B.1.617.2 – the “Indian variant”.

Online newspaper VnExpress said Long had described the new variant as a hybrid of the Indian and UK variants.

“The new one is an Indian variant with mutations that originally belong to the UK variant,” Long was quoted as saying, adding that authorities would soon announce the name and detailed characteristics of the newly discovered variant.

Officials at the World Health Organization did not immediately respond to a request for comment.

Laboratory cultures of the new variant, which is much more transmissible than the previously known types, revealed that the virus replicated itself very quickly, Long was quoted as saying.

He said that could explain why so many new cases had appeared in different parts of the country within a short period of time.