The Ministry of Health (MOH) confirmed 657 new Covid-19 cases in Singapore as of noon yesterday, 95 per cent of whom were migrant workers in dormitories.

An 86-year-old Singaporean woman died from complications due to the virus the same day, the 18th death from Covid-19 here.

MOH said she was confirmed to have the infection on April 27, and had a history of diabetes, hypertension and hyperlipidaemia, which refers to high levels of lipids, such as cholesterol, in the blood.

Khoo Teck Puat Hospital has contacted her family and is extending assistance to them, added MOH.

Six new clusters were identified. These are at NCS Hub in 5 Ang Mo Kio Street 62, 16 Fan Yoong Road, 15 Gul Way, 23 Sungei Kadut Street 2, 9A Tech Park Crescent, and 64 Woodlands Industrial Park E9.

Meanwhile, a cluster at a Maxwell MRT station work site has been closed after no new cases were linked to it for 28 days.

Yesterday was the 10th day in a row where daily cases were below 1,000. The new cases bring the total number in Singapore to 18,205.

Work permit holders residing in dormitories make up 626 of the new cases. MOH said the number of migrant worker cases has been fluctuating in recent days as a laboratory was clearing backlogged cases.

It added it is working with the laboratory to stabilise its operations.

New local cases outside dormitories include 10 Singaporeans and permanent residents, and three work pass holders. There were no imported cases.

One of the new cases is a 34-year-old Singaporean nurse from the Health Promotion Board who was working at the Singapore Expo community care facility, said MOH.

She was confirmed to have Covid-19 on Saturday and is now warded at the National Centre for Infectious Diseases.

She did not travel to countries or regions affected by the coronavirus recently, and had not gone to work since she had symptoms.

MOH said 61 more cases have been discharged from hospitals or community isolation facilities, bringing the total number of those who have fully recovered to 1,408.

There are 1,630 confirmed cases still in hospital with 22 in critical condition in the intensive care unit. Community isolation facilities have another 15,149 cases.

Of the new cases, 87 per cent are linked to known clusters, while the rest are pending contact tracing.

New local cases excluding those in dormitories and other work permit holders have dropped to an average of 11 a day the past week, from 21 the week before.

The average daily number of such unlinked cases has also decreased to five from 13, over the same period.

In the past week, from April 26 to May 2, MOH has uncovered links for 821 previously unlinked cases.

Education Minister Ong Ye Kung said yesterday that precautions will be taken to keep students safe as they are allowed back to school from May 19. But attendance will not be compulsory.

On Saturday, the multi-ministry task force tackling the coronavirus said tighter restrictions on activity will be extended for another week, and some businesses like barbers, home-based bakers and laundry services will be allowed to resume operating on May 12.