Singapore now has 10 active Covid-19 clusters.
The latest case is a 59-year-old trailer truck driver who works at Brani Terminal and Pasir Panjang Terminal, said the Ministry of Health (MOH).
The Singaporean employed by GKE Express Logistics was last at work on May 1.
He developed a fever and sore throat on Sunday (May 2), and remained at home.
The next day, he sought medical treatment at a general practitioner clinic and was tested for Covid-19.
His result came back positive on Tuesday, and he was conveyed in an ambulance to Alexandra Hospital. His serology test result is pending, said MOH.
The earliest case in the cluster is a 23-year-old Indian national who works as a lashing specialist at the Pasir Panjang Terminal and was confirmed to have Covid-19 on April 10.
As a precautionary measure, MOH will carry out special testing operations to test port workers employed by PSA Singapore who have been deployed at the terminal.
This comes as community infections surge in Singapore, with cases increasing to 62 in the past week from 13 in the week before.
The number of unlinked cases has also risen to seven cases from six over the same period.
There were also 15 imported cases who were placed on stay-home notice on arrival in Singapore, said MOH.
In all, 16 coronavirus cases were reported on Wednesday, taking Singapore's total to 61,268.
A POSB branch in Kaki Bukit Recreation Centre was added to the list of locations visited by Covid-19 cases linked to Tan Tock Seng Hospital (TTSH) while they were still infectious, MOH said.
The branch was visited between 10.05am and 11.30am on April 27.
People who have been to these places should get tested for the virus, which is free for them, the authorities said on April 30.
Chinatown Complex Food Centre, Clementi 448 Market & Food Centre and ST 11 Coffee House were added to the list of locations visited by Covid-19 cases while they were still infectious, MOH said on Wednesday night.
Those identified as close contacts of confirmed cases would already have been notified, MOH added.
Individuals may access the SafeEntry Location Matching Self-Check service via the TraceTogether App, SingPass Mobile, or at this website to check whether they were at these locations during the specified timings, based on their own SafeEntry records.
There is no need to avoid places where confirmed cases of Covid-19 have been as the National Environment Agency will engage the management of affected premises to provide guidance on cleaning and disinfection, said MOH.
With 21 cases discharged on Wednesday, 60,829 patients have fully recovered from the disease.
A total of 131 patients remain in hospital, including two in critical condition in the intensive care. They are not linked to the TTSH cluster.
Another 262 patients are recuperating in community facilities.
Singapore has had 31 deaths from Covid-19 complications, while 15 who tested positive have died of other causes.