The Ministry of Health (MOH) removed two community cases it had announced earlier yesterday, after further tests confirmed the individuals did not have Covid-19.
Initial tests showed they were borderline-positive.
In an update last night, the ministry revised the number of community cases from three to one. The sole case is a permanent resident.
Among the 15 imported cases reported yesterday were four special pass holders who are crew members of a ship that arrived from Malaysia on Sept 23.
They did not disembark, and were subsequently sent to a hospital after testing positive for Covid-19 while on board.
The other imported cases counted three Singaporeans and two permanent residents among them, with the others being long-term pass holders, and one on a short-term visit pass.
Eight arrived in Singapore from India between Sept 17 and Sept 28, including two Singaporeans. The third Singaporean returned from Indonesia on Sept 19. The remaining two imported cases came from France and the Philippines.
MOH confirmed 19 new coronavirus cases yesterday, taking Singapore's total to 57,784.
Separately, Junction Nine in Yishun and the Orchis Food Court at Changi Airport Terminal 1 were among places visited by Covid-19 patients while they were infectious.
MOH provides a list of locations that infectious Covid-19 patients visited for at least 30 minutes to get people who were at those places at the same time to monitor their health. Close contacts would already have been notified and there is no need to avoid these places, which would have been cleaned if necessary, said MOH.
Migrant workers living in dormitories made up the remaining three patients.
Update on cases
New cases: 19
Imported: 15 (3 Singaporeans, 2 permanent residents, 2 student's pass holders, 2 work pass holders, 1 work permit holder, 4 special pass holders, 1 short-term visit pass holder)
In community: 1 (1 PR)
In dormitories: 3
Active cases: 245
In hospitals: 44 (0 in ICU)
In community facilities: 201
Patients with Covid-19 who died of other causes: 15
Total discharged: 57,497
Discharged yesterday: 24
TOTAL CASES: 57,784
One was identified earlier as a contact of previous cases, and had been quarantined to prevent further transmission. He was tested during quarantine.
The other two were detected through surveillance testing.
The number of new daily cases in the community has remained stable at an average of fewer than one case a day in the past two weeks.
The number of unlinked cases in the community has also remained stable at an average of fewer than one case a day in the same period.
With 24 cases discharged yesterday, 57,497 patients have fully recovered from the disease.
Forty-four patients remain in hospital, with none in intensive care, while 201 are recuperating in community facilities.
Singapore has had 27 deaths from Covid-19 complications, while 15 who tested positive have died of other causes.
The number of new daily cases in the community has remained stable at an average of fewer than one case a day in the past two weeks. The number of unlinked cases in the community has also remained stable at an average of fewer than one case a day in the same period.