SINGAPORE - Residents living in seven Housing Board blocks in Redhill Lane and Redhill Close will have to undergo mandatory Covid-19 testing after viral fragments were detected in wastewater samples collected from some blocks.

The Ministry of Health (MOH) said on Monday (June 21) that it is investigating likely Covid-19 transmission in Redhill following the finding.

Investigations are ongoing to determine the source of transmission, said the ministry.

The affected blocks are 81, 82 and 83 Redhill Lane and 87, 88, 89 and 90 Redhill Close.

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

"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 protect the community from further transmission," said the ministry.

Visitors and those who have come into contact with residents from these blocks 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.

Testing will take place at the pavilion at 84A Redhill Lane and at the void deck of 89 Redhill Close from Monday to Wednesday.

Residents must take 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."

Mr Melvin Yong, MP for Radin Mas, said on Monday that the mandatory testing is a "precautionary measure to ensure the safety and well-being" of the affected residents.

They will be notified via SMS of their assigned swabbing time slots, and will be assigned to either of the two temporary testing centres, he added in a Facebook post.

"For residents living in the surrounding blocks, there is no need for you to get tested at this point unless you have visited someone at these affected blocks, between June 6 and 20," said Mr Yong.

He urged residents to stay home as much as possible, to wear their masks when going out and to go to a doctor promptly if they are feeling unwell.