India"s health officials raised warning flags on Wednesday as the country reported a massive 55 percent daily spike in COVID-19 infections with 58,097 new cases, double what it reported just four days ago. Health officials said the surge was largely caused by the Omicron variant which was rising exponentially in the bigger cities. The country also reported its first official death from the variant, an elderly man with severe diabetes in Rajasthan, Deutsche press agency (dpa) reported. Tracking the new variant will be aided by a recently approved testing kit that helps to identify the Omicron variant in a polymerase chain reaction (PCR) test, the officials said. The positivity rate of Covid-19 - that is the percentage of tests that turn out positive - had increased by six times in just a week and this was a cause of concern, the officials said at the weekly briefing. While most cases of Omicron so far had turned out to be mild and not requiring hospitalization, there was no room for complacency. The steep surge could lead to such a large number of cases that even if a small percentage of them required hospitalization it could overwhelm the health infrastructure, the health officials said. Regional governments were encouraged to boost testing and hospital facilities and expand temporary COVID-care facilities to hotels and other available places that could be linked to hospitals. There was also concern as large numbers of health-care workers in Delhi, Mumbai and other cities contracted COVID-19. The governments of Delhi and Karnataka announced restrictions on all movement at the weekend, except essential goods and services, hoping to keep people at home and restrain the rapid rise in infections. Officially the number of Omicron cases is 2,135, but with limited capacities for genome sequencing the actual numbers are estimated to be much higher. Maharashtra and Delhi reported the largest number of Omicron cases, according to a Health Ministry update. Travel and the opening of shops and establishments at night have been restricted in several states. In the city of Kolkata, which has reported one of the highest positivity rates, many residents had to wait for two days to get a reverse transcription PCR test, considered the most reliable test in India. The opposition Indian National Congress party has put on hold all election rallies and door-to-door campaigns in Uttar Pradesh, one of the five states scheduled to go to the hustings soon. The rallies by political parties are being held despite the surge in Covid-19 cases. India faced a virulent second wave of infections driven by the Delta variant between April and June that overwhelmed the health infrastructure and left tens of thousands dead. The country of 1.3 billion has a caseload of Covid-19 so far at 35 million, second only to the United States. — Agencies