Not a single traveller arriving in Mumbai from the “countries of concern” since November 12 has tested Covid-positive, though the BMC has collected their samples for another round of RT-PCR tests, said officials on Monday. In the case of a Covid-positive Dombivli man who came from Omicron-hit South Africa, the genome sequencing report will come after about 5 days.

The reports of the 100 city residents are expected tomorrow, said officials. The “countries of concern” include South Africa, Zimbabwe, Botswana, Mozambique and a few Middle Eastern and European nations. With the world in the grip of Omicron fear, the civic body is on its toes to trace passengers and their high-risk contacts in the past 20 days, which also saw 466 flyers, who are residents of Maharashtra, landing at Mumbai airport.