One in 10 passengers aboard two flights that landed in the Netherlands from South Africa on Friday tested positive for Covid-19, Dutch authorities said Saturday, as governments restricted travel to hinder the spread of the new Omicron variant.

Sixty-one of 600 passengers from South Africa tested positive, health authorities said, adding that they were still analyzing whether those with a positive result had been infected with the new strain. Passengers who tested positive for Covid-19 will be placed in isolation at a hotel, while passengers with negative results can leave the airport or continue travel.