Singapore imposed mandatory screening for tuberculosis in an apartment block after about 170 people tested positive for the infectious disease.
Stallholders, shop owners and their employees who are located in the complex will also be tested, the Ministry of Health said in a statement Friday.
An earlier voluntary round of screening found about 30 percent of 574 residents and workers testing positive, and those who have not participated must now do so.
The health ministry said tuberculosis is endemic in Singapore, and is not uncommon in Singaporeans.
The prevalence of tuberculosis infection as high as 29 percent among those aged 70 to 79 years, and is curable.
Its spread is also preventable, the government said.