A senior Botswana health official said on Tuesday that 16 out of the total 19 cases of the Omicron coronavirus variant detected in the country were asymptomatic, and it was “unfair” to treat the country as ground zero of the new variant.

Pamela Smith-Lawrence, Acting Director of Health in the Ministry of Health and Wellness, told Reuters in an interview that the majority of the 19 people who were found to be infected with the new Omicron variant have already tested negative.

While 16 people were asymptomatic, the remaining three had “very, very mild” symptoms.

Botswana on Friday said the country was investigating certain mutations of the coronavirus that were found in four foreign nationals who were in the country on a diplomatic mission. Since then the country has reported another 15 cases of the new variant, taking the total number to 19.

While it is still not established where Omicron first emerged, on Nov. 25 South Africa, followed by Botswana a day later, announced they had detected a new variant whose mutations were different from the dominant Delta variant.

This prompted immediate air travel curbs on southern African countries from several European and Asian countries, a decision which has been criticised by both South Africa and Botswana.

The four foreign nationals, aged between 30 and 65 who had come to Botswana on Nov. 7, were tested positive on Nov. 11 and on further investigation their samples showed new mutations on Nov. 22, Smith-Lawrence said, adding the government uploaded the data on the international database the next day.

“Unfortunately… finger now points to Botswana to say it originated in Botswana, or it is a Botswana variant, which I think it’s quite unfair and unnecessary at this time,” she said, adding that 14 out of the 19 people so far detected with the variant were foreign nationals.

She declined to name the nationalities of the people or from where they had flown.

She said within the next two to three weeks the government would be in a position to give more clarity on whether Omicron is more virulent than its predecessors or not.