SINGAPORE - Three more foreign worker dormitories have been placed under isolation, as Covid-19 cases in such facilities continue to rise.

Health Minister Gan Kim Yong has declared Shaw Lodge Dormitory, North Coast Lodge and Tuas View Dormitory as isolation areas under the Infectious Diseases Act, according to a notice on the Government Gazette on Thursday (April 16). The move comes into effect on Friday.

There are now a total of 12 dormitories declared as isolation areas where workers at these lodgings must be quarantined in their rooms for 14 days.

All three dormitories are linked to existing clusters of coronavirus cases here.

Shaw Lodge Dormitory in Tai Seng had four cases linked to the cluster announced on Thursday night in the Ministry of Health's daily update, bringing the number of infections to 28.

For North Coast Lodge in Woodlands, eight blocks have been declared isolation areas. On Thursday, eight cases were linked to the cluster, bringing its number of infections to 26.

At Tuas View Dormitory, 20 blocks have been declared isolation areas. The dormitory had 30 cases linked to its cluster on Thursday, bringing its total to 73 cases.

The other nine dormitories gazetted as isolation areas are Mandai Lodge 1, Cochrane Lodge I, Cochrane Lodge 2, Acacia Lodge, Tampines Dormitory, Sungei Tengah Lodge, S11 Dormitory @ Punggol, Westlite Toh Guan and Toh Guan dormitory.

Singapore saw its sharpest single-day spike of 728 new coronavirus cases on Thursday, bringing the total number of cases here to 4,427.

Foreign workers living in dormitories made up 654, or almost 90 per cent, of these new cases, with two more large purpose-built dorms and three other factory converted dorms emerging as new clusters.

While the spread of the virus in the wider community has held steady over the past two weeks, the number of cases linked to foreign workers in dormitories has risen exponentially over the past two weeks.

The total number of foreign workers linked to dorms who have tested positive for Covid-19 is 2,689 - about 60 per cent of all Singapore's cases.