India's Delhi region will test every confirmed Covid case for Omicron, amid concerns the highly transmissible variant could have a more adverse impact than the Delta wave that hit the country early this year. The number of Omicron cases in India rose to 166 on Monday after infections were detected in several areas, including the capital New Delhi. The city’s total tally jumped to 28 after four new cases of Omicron were confirmed. On Sunday, 107 cases were detected in the capital, the highest since July. India detected its first Omicron case in southern Karnataka state on December 2 and has since witnessed a steady surge in the number of infections. Most of the Omicron cases were found among travellers. The federal government has warned an Omicron-driven outbreak could result in 1.4 million cases a day. Delhi’s chief minister Arvind Kejriwal said all the positive cases in the city would be sent for genome sequencing. He assured residents the city has adequate health infrastructure to deal with any eventuality. “Suddenly cases have jumped in a day,” Mr Kejriwal told reporters. “So far we were testing only passengers at the airport but now all positive cases in Delhi will be sent for genome sequencing for Omicron.” Mr Kejriwal said there was “no need to panic” and ordered four state-run hospitals to set up isolation wards for travellers coming in from at-risk countries. In Karnataka state, five more cases were detected on Monday, state health minister Dr K Sudhakar said. All the patients had been inoculated with two doses of Covid vaccines and their travel history and contacts with international travellers are being ascertained. Six more people were confirmed infected in western Maharashtra state. Its capital, Mumbai, has imposed a ban on gatherings and urged people to avoid assembling during the coming Christmas and New Year festivities. “Avoid any kind of crowding, wear masks and follow Covid-19 guidelines. All citizens must also get fully vaccinated,” Municipal Commissioner Iqbal Singh Chahal said. India witnessed a brutal second wave, blamed on the Delta variant in April and May, that affected more than 20 million people. More than 160,000 people died from the virus in the two months, the National Centre for Disease Control said. The health ministry on Monday said more than 6,563 new cases of Covid-19 were confirmed across the country. The total caseload stood at around 34 million, with over 477, 000 deaths — the third-highest in the world.