Nine more people, including four primary school pupils, who tested positive for Covid-19 have been linked to the Learning Point tuition centre cluster.

They comprise pupils from Kong Hwa School, Yu Neng Primary School and St Margaret's Primary School.

This takes the total number of cases in the cluster to 18, after a 50-year-old woman who works as a tutor there was confirmed to have Covid-19 last Wednesday.

The new cases are part of 38 new community infections in Singapore yesterday. There were also 11 imported cases.

The tuition centre was among several clusters that have expanded in Singapore, according to figures released by the Ministry of Health (MOH) last night.

There are two more cases in the Changi Prison cluster - a 35-year-old male Chinese national who works as a cargo driver at Sats Food Services and a 22-year-old male Vietnam national who is unemployed.

They are household contacts of the chef who works at Changi Prison Complex and tested positive for Covid-19 last Thursday. There are now four cases in the cluster.

Meanwhile, the cluster at Changi Airport Terminal 3 had six more cases, including a one-year-old Singaporean boy. He is a family member and household contact of a 44-year-old Singaporean man who works as a private-hire driver at Gojek and had visited the terminal on May 6. The man was confirmed to have Covid-19 last Wednesday.

The boy was placed on quarantine last Thursday, and developed a fever and runny nose two days later. His test result came back positive on the same day, and his serology test result is pending.

A 39-year-old male Philippine national who works as a nurse at Ren Ci Nursing Home (Ang Mo Kio) also tested positive and was linked to the cluster.

He is a household contact of a 37-year-old male Philippine national who was also among the cases announced yesterday. The man works as a sales representative at JR Life Sciences and had visited Changi Airport Terminal 3 on May 4.

There are now 74 cases in the Changi Airport Terminal 3 cluster, which is the largest cluster.

There was also one more case in the Wok Hey (White Sands) cluster - a 26-year-old Singaporean woman who works as a customer service officer at Wareesan Management.

She is a family member and household contact of two previously confirmed cases.

MOH is making special swabbing arrangements for all tenants and staff who have been working at White Sands Mall and the Giant outlet at Block 440 Pasir Ris Drive 4 since May 2, as some visitors to these venues have tested positive for the virus in the past two weeks.

The testing is mandatory for all tenants and staff, and will be held at White Sands today and tomorrow, said Senior Minister and Coordinating Minister for National Security Teo Chee Hean in a Facebook post yesterday.

Meanwhile, there were 17 unlinked community cases yesterday, including a 29-year-old female Philippine national who works as a nurse at Raffles Hospital.

She arrived from the Philippines on April 1 and served her stay-home notice at a dedicated facility until April 14. Her swab test done on that day came back negative for Covid-19.

She is asymptomatic and was detected when she was tested last Friday, as part of rostered routine testing for healthcare workers.

Her test result came back positive the next day, and her serology test result is pending. She received her first dose of the Covid-19 vaccine on May 8.

Another unlinked case is a 52-year-old male permanent resident employed by Certis as an auxiliary police officer at Bank of China at Westgate.

He developed a fever, cough and body aches last Thursday, and sought medical treatment the next day at a GP clinic, where he was tested for Covid-19.

The test came back positive two days later, and his serology test result is pending.

He has preliminarily tested positive for the B1617 variant, pending further confirmatory tests.