People inside a shopping mall in Singapore on May 15, 2021, ahead of tightening restrictions over concerns of a rise in Covid-19 coronavirus cases.Roslan Rahman | AFP | Getty ImagesSINGAPORE — Covid restrictions in Singapore have been extended for four more weeks, authorities announced Wednesday after new daily cases hit a record high of 3,994 on Tuesday.The curbs, which include limiting group sizes for social gatherings and making work from home the default, will now be in place until Nov. 21, with a review due at the two-week mark.”At the current situation, we face considerable risk of the health-care system being overwhelmed,” Finance Minister Lawrence Wong said during a press briefing on Wednesday.Those measures were meant to take effect from Sept. 27 to Oct. 24, and health authorities said they would review the restrictions again based on the Covid situation.Singapore has tightened and loosened restrictions several times this year, easing them in response to the number of Covid cases. The government has said repeatedly that it wants to ensure the health-care system is not overwhelmed.At the same press briefing, Health Minister Ong Ye Kung said the record number of cases is likely to be a post-weekend spike.On Tuesday, the health ministry said local hospitals were under “significant pressure and strain” as the number of patients in the intensive care unit rose to 71, according to official data released.Of 1,650 isolation beds in public hospitals, 89% have been filled, a press release from the health ministry said. Around 67% of ICU beds are occupied, though a number of patients were admitted for monitoring purposes, the release said.”If need be, we will open up more ICU beds,” Ong said. “The next leap will be to 300 beds, but that will be at the expense of further degradation of normal service and normal medical care.”Health authorities also encouraged people to limit their social activities and said Tuesday that more people visited malls or took public transport in the past week.The number of unvaccinated seniors being infected increased to around 100 a day, the health ministry said, noting that this group was particularly vulnerable and at risk of falling very sick.A total of 1,738 cases are in hospital as of Tuesday, with 338 people requiring oxygen supplementation, official data showed. The vast majority of cases in the last 28 days had either no symptoms or mild symptoms.Since the start of the pandemic, Singapore has reported 154,725 cases, and around 84% of its population has been vaccinated. Some 246 people have died from Covid-19 in the Southeast Asian country of about 5.45 million people.