SINGAPORE - Residents living in four Housing Board blocks in Sims Avenue will have to undergo mandatory Covid-19 testing, after viral fragments were detected in wastewater samples collected from the blocks.

The Ministry of Health (MOH) said on Thursday (July 22) that it is investigating likely Covid-19 transmission at Blocks 842, 844, 846 and 848 Sims Avenue that are located near Geylang Serai Market.

Investigations are ongoing to determine linkages and the source of transmission, added the ministry.

Testing is optional for those who have tested negative for Covid-19 infection from last Saturday onwards.

Mandatory testing will be conducted at the pavilion at 3 Geylang Serai from Thursday to Friday, between 9am and 4pm.

"In the event that a positive Covid-19 case is detected, MOH will isolate the case, identify all close contacts, test and quarantine them to prevent the community from further transmission," said the ministry.

Visitors and those who have come in contact with residents from these blocks between July 6 to Tuesday may also volunteer for Covid-19 testing.

This will help to detect asymptomatic cases in the community, said MOH.

"We encourage these individuals to come forward for testing," the ministry added.

Voluntary testing will take place by appointment only at designated regional screening centres from Thursday to Saturday and at the pavilion at 3 Geylang Serai from Friday to Saturday, between 9am and 4pm.

Residents must bring along their NRIC for identification purposes.

MOH said it has distributed leaflets and sent SMSes to the affected residents to provide them with more information.

"Those who are still awaiting their test results are advised to minimise social interactions as much as possible," said MOH. "They should continue to monitor their health and seek immediate medical attention if they feel unwell."

Those who wish to book an appointment or need more information on the alternate test locations can visit this website or call 1800-333-9999.