A man among the six community Covid-19 cases announced yesterday met a large group of people for sports and social activities.

The Ministry of Health (MOH) said that it will be investigating the case, and that the man's behaviour increases the risk of transmission and has caused his contacts to be quarantined.

"We advise the public to abide by the spirit of the rule to limit social gatherings to not more than five people," it said.

When asked, MOH would not say which new community case met the large group of people.

It said yesterday that two of the six new community cases are from the public health sector.

One of them is a 23-year-old Singaporean who is a nurse at Ng Teng Fong General Hospital (NTFGH) and was confirmed to have Covid-19 on Thursday. He had not gone to work since the onset of symptoms on Monday. He is linked to a previously announced case and is hospitalised at NTFGH.

The second case is a 27-year-old Singaporean who works at Vanguard Senior Care Centre in Woodlands. She is asymptomatic and unlinked to other cases. She is warded at the National Centre for Infectious Diseases.

The ministry said she is likely to be a case of a past infection and is no longer infectious.

In a separate statement, the Agency for Integrated Care (AIC) said that the woman has been mostly working from home since the circuit breaker period, but was last at the centre on Thursday, the same day she tested positive.

The centre is located in the same building as Vanguard Woodlands Care Home but they are served by separate teams who have not been in contact since before the circuit breaker, AIC said.

It added that the woman did not have any contact with the staff and clients who use the centre's community rehabilitation services, which resumed on June 15.

The agency said contact tracing is ongoing and those who had close contact with the staff will be quarantined and tested. The centre has also been cleaned and disinfected to reopen on Monday.

MOH said that from June 3, it has been conducting surveillance tests for non-residential community care staff in places such as kidney dialysis centres, home care services, day hospices and senior care centres. To date, more than 5,500 out of an estimated 5,700 staff have been tested and she is the only one who tested positive.

The remaining community cases are three Singaporeans and a work pass holder.

One of these patients had been picked up as a result of the ministry's proactive surveillance and screening as he works in a dormitory, and two had already been placed on quarantine. The work pass holder is a 48-year-old Indian national who is linked to the cluster at Keppel Shipyard.

Migrant workers staying in dormitories make up the remaining 213 cases, taking Singapore's total to 42,955.

MOH added Safra Mount Faber, Jurong East Sports Centre, Pearl's Hill 34 at 34 Upper Cross Street, Outram Park Ya Hua Rou Gu Cha at 7 Keppel Road and People's Park Centre to the list of public places visited by Covid-19 patients while they were still infectious.

It also announced a new cluster in a dormitory at 143 Tuas View Square.

With 221 cases discharged yesterday, 36,814 patients have fully recovered from the disease.

A total of 183 patients remain in hospital, including one in the intensive care unit, while 5,921 are recuperating in community facilities.

Singapore has had 26 deaths from Covid-19 complications, while 11 who tested positive have died of other causes.