Mumbai, Dec 7 (PTI) The number of COVID-19 positive air travellers who have returned to Mumbai from "at-risk" countries climbed to 17 on Tuesday with the addition of one more patient to the list, the city civic body said.The Brihanmumbai Municipal Corporation (BMC) said these 17 foreign returnees to the city - 13 males and four females - have tested positive for COVID-19 and have been hospitalized.In a statement, the civic body said so far nine close contacts of these patients - five women and four men - have also tested positive for coronavirus.Till Monday, 16 travellers arriving from at-risk countries and their nine close contacts had tested positive to COVID-19.One more returnee was added to the list on Tuesday, taking the tally to 17, the BMC said.All coronavirus positive air travellers have been admitted to hospitals and their swab samples sent for genome sequencing to find out if they are infected with the new Omicron variant of the virus, the release said.Genomic sequencing is a process to decode genes in SARS-CoV-2, which causes COVID-19, to help scientists find which variant might be present in swab samples.On Monday, a 37-year-old man who returned to Mumbai from South Africa on November 25 and his 36-year-old close contact, a woman who landed at the city airport from the US the same date, were found infected with the Omicron strain. They were the first two cases of the new variant detected in Mumbai.Maharashtra has so far reported 10 cases of the new variant.However, no new infection of Omicron came to light in the last 24 hours, the state health department said.The BMC has been carrying out COVID-19 tests on international travellers who are arriving at the Mumbai airport from at-risk countries to check if any of them is infected with Omicron, classified as a "variant of concern" by the WHO.Passengers arriving from these nations, where Omicron cases have been detected, have to follow additional COVID-19 testing and quarantine measures.Countries in Europe, including the UK, and South Africa, Brazil, Botswana, China, Ghana, Mauritius, New Zealand, Zimbabwe, Hong Kong, Singapore, Tanzania and Israel have been placed in the at risk category, according to the Civil Aviation Ministry.According to the Union Health Ministry"s guidelines that came into force from December 1 following the emergence of Omicron, all passengers coming from at-risk countries have to compulsorily undergo RT-PCR test and 2 per cent of travellers arriving from other nations would have to take the test on a random basis. PTI KK RSY RSY