KOLKATA, India, Jan 1 (Reuters) - India on Saturday reported 22,775 new COVID-19 infections over the past 24 hours, health ministry data shows, adding to concerns for authorities around the country about the rising number of cases. The data indicates that thickly populated metros, such as the national capital New Delhi, financial centre Mumbai and Kolkata in the east, are seeing some of the sharpest rises. In the eastern state of West Bengal, infections rose to 3,450 in the last 24 hours with at least 1,950 cases reported in Kolkata, the capital. Sixteen Omicron cases have been reported in West Bengal. Kolkata"s municipal corporation declared 17 micro containment zones in residential clusters where more than 5 infections have been reported. People living in the zones are not allowed to leave the area to try to contain the spread of the disease. Ajoy Chakrobarty, the state"s director of health services, said he was holding meetings with private hospitals to ensure health facilities are ready to deal with the rising number of cases. India witnessed a devastating second wave of COVID-19 last year when the daily average number of new cases peaked at around 400,000. Caseloads had dropped significantly since then. For many months the national tally remained well under 10,000 cases a day. Now, officials and medical experts fear the Omicron variant might fuel a third wave of the disease.