Singapore's health ministry on Thursday reported 24 locally transmitted COVID-19 cases, the highest daily number since mid-September, with 17 of the fresh cases linked to a cluster at Changi Airport.
Authorities had started testing all workers at the airport a few days ago after detecting the cluster. They have also restricted access to terminals to only passengers with tickets and essential workers for two weeks from Thursday.
Following months of reporting few new local cases, infections in Singapore have been climbing, prompting authorities to tighten social distancing rules from last week.
As of Wednesday, the number of unlinked cases in the community increased to 12 in the past week from seven in the week before, according to a health ministry statement.
Though Singapore's daily cases are only a fraction of the numbers being reported among its Southeast Asian neighbours, a jump in infections would be a setback for the Asian business hub, which has successfully contained its earlier outbreaks.
The new cases come as Singapore readies a travel bubble with Hong Kong that is due to begin on May 26 after a suspension last year. The city-state is also set to host the Shangri-La Dialogue security summit early next month and the World Economic Forum's annual summit in August.
Singapore has reported more than 61,000 virus cases, with the bulk linked to outbreaks in foreign worker dormitories, and 31 deaths. None of Thursday's new cases are from the dormitories, the preliminary report said.