As many as nine people have tested positive for the Omicron variant of coronavirus in Rajasthan's Jaipur district, officials said on Sunday. The patients include four members of a family who had recently returned from South Africa. Their samples were sent for genome sequencing to Jaipur’s state-run Sawai Man Singh Hospital.With this, the total number of people infected the strain across India has reached 12.A total of seven more people were detected with the variant in Maharashtra's Pune on Sunday too. “Four persons in Pune who returned from foreign tours and three of their close contacts have tested positive for the Omicron variant," said the Maharashtra health department.Among those who have been affected is a woman who came from Nigeria along with her two daughters. The woman's brother and his two daughters have also tested positive, said officials.Another case is of a man from Pune who returned from Finland the last week.The first two cases of Omicron were reported in Karnataka. On Saturday, the third case was reported from Gujarat's Jamnagar. Later, a man from Maharashtra who travelled to Mumbai from South Africa via Dubai and Delhi was found positive for the new variant too.Delhi reported its first and the country's fifth Omicron case on Sunday morning. The patient, a Tanzania returnee, has mild symptoms as he had taken both doses of the vaccine.A new variant of Covid-19 was first reported to the World Health Organisation (WHO) from South Africa on 25 November. As per the WHO, the first known confirmed B.1.1.529 infection was from a specimen collected on 9 November this year.On 26 November, the WHO named the new Covid-19 variant B.1.1.529 as 'Omicron'. The WHO has classified Omicron as a 'variant of concern'.To deal with this, several countries have imposed travel restrictions and local lockdowns.India has added several countries to the “at-risk" list from where travellers would need to follow additional measures on arrival in the country, including post-arrival testing for infection.According to the Centre, the countries designated as "at-risk" include the UK, South Africa, Brazil, Botswana, China, Mauritius, New Zealand, Zimbabwe, Singapore, Hong Kong and Israel.