Singapore has warned it may need to reimpose COVID-19 restrictions if a new outbreak of the highly infectious Delta variant is not contained, putting at risk the city's shift towards living with the virus. The number of new COVID-19 infections in Singapore doubled in the past week, according to the country's Ministry of Health, rising to more than 1,200 cases for the week ending Sept. 5. To date, Singapore has recorded a total of 68,901 COVID-19 infections and 55 deaths, according to Johns Hopkins University. On Monday, Lawrence Wong, head of Singapore's COVID-19 task force, said it isn't just the total number of daily cases that is concerning the Singaporean government, but also "the rate at which the virus is spreading." "We know from the experience of other countries that when cases rise so sharply there will be many more ICU cases and many more people succumbing to the virus," he said. Singapore pursued an aggressive "COVID zero" policy during the pandemic, imposing tight restrictions including shutting restaurants, closing borders and enforcing social distancing. But in June, the government announced it was planning to move toward a living with COVID strategy — attempting to control outbreaks with vaccines and monitoring hospitalizations rather than restricting citizens' lives. "The bad news is that COVID-19 may never go away. The good news is that it is possible to live normally with it in our midst," Singapore's top COVID-19 officials wrote in an op-ed in June. Singapore has one of the highest COVID-19 vaccinations rates in the world, with more than 80% of the population fully vaccinated. Throughout August, Singapore began to relax some of its COVID-19 restrictions, allowing fully vaccinated people to dine in restaurants and to gather in groups of five, up from two. But the new outbreak has halted any further re-openings, Singapore's COVID taskforce chief Wong said on Monday. Wong said Singapore would attempt to contain the new outbreak through more aggressive contact tracing and by "ring-fencing" cases and clusters. Mandatory testing for high-risk workers will also happen more frequently — once a week instead of once every two weeks. And the list of workers subjected to mandatory testing will be expanded to include retail, delivery and public transport staff. Singapore has also banned all workplace gatherings from Wednesday, and Wong encouraged citizens to avoid unnecessary social events while they attempt to contain the outbreak. He said it was a reflection of Singapore's new policy and high vaccination rates that the country was able to maintain a level of openness during the new outbreak. "But if despite our best efforts, we find that the number of serious cases needing oxygen in ICU care goes up sharply, then we may have no case but to tighten our overall posture, so we should not rule that out," he said. Singapore's outbreak comes as other countries in the region, which were previously aiming for zero infections, move towards a similar living with COVID-19 model. Millions of residents in the Australian states of New South Wales and Victoria have been living in lockdown for months as local authorities attempted to contain Delta outbreaks. They have since conceded that won't be possible. The Australian government announced in August that once 70% of people over 16 receive two doses of vaccine, there will be a steady easing of restrictions. Only 38.4% of Australia's population was fully vaccinated as of Monday. But some Australian state leaders have warned against opening state borders prematurely, questioning why they would willingly expose their populations to the virus. Western Australia and Queensland currently have zero COVID-19 cases in the community. "We have some of the freest, most open, exciting communities in the world, and we want to keep it that way while we get our population vaccinated," said Western Australia Premier Mark McGowan on Aug. 30. "The idea that we would prematurely decide to deliberately import the virus ... is complete madness," he added. Some epidemiologists say if restrictions are eased before vaccination rates in vulnerable communities are high enough, the results could be catastrophic. — CNN