Singapore has ramped up efforts to eradicate the Zika virus in the country after the number of domestic cases doubled from 41 to 82.
Meanwhile, the United States and Britain joined Australia, Taiwan and South Korea in advising pregnant women to avoid non-essential travel to the country.
The heath ministry of Singapore has advised pregnant women with symptoms of Zika, as well as pregnant women with male partners who have tested positive, to get tested.
"We advise pregnant women to undertake strict precautions against mosquito bites and seek medical attention immediately if they become symptomatic," the health ministry said in a statement late Tuesday.
— Singapore Government (@govsingapore) August 31, 2016
As infections climbed, environmental agency workers stepped up efforts to eradicate mosquitoes that spread the disease, expanding a fumigation campaign centred on the "ground zero" of the outbreak, a construction site housing foreign workers in the eastern suburb of Aljunied.
Another nearby area - Paya Lebar Way - was also smothered with mosquito-killing chemicals.
Singaporean authorities said they tested 124 people, primarily foreign construction workers employed at a construction site. That site has been ordered to halt work while workers' dormitories are being inspected.
Seventy-eight people tested negative and five cases were pending. Thirty-four patients had fully recovered.
Zika, which has been detected in 58 countries including hardest-hit Brazil, causes only mild symptoms for most people, such as fever and a rash.
But if pregnant women are infected, their babies are at risk of being born with microcephaly, a deformation in which babies suffer from abnormally small brains and heads.
Construction workers in the affected areas have been given mosquito-repellent patches, chewable Vitamin C tablets and removable sleeves to cover their arms.
Authorities have also deployed "gravitraps" -- devices which attract pregnant mosquitos and trap their larvae.
Since Singapore reported its first locally transmitted Zika infection on Saturday, confirmed cases have climbed quickly as authorities ramped up testing.
Singapore's first reported case of Zika in May involved a man who had visited Sao Paulo, Brazil earlier in the year.
Neighbouring countries such as Malaysia, Indonesia and the Philippines have said they will monitor visitor arrivals from Singapore.