Singapore has been praised for limiting the spread of the coronavirus.But infections have risen recently among migrant workers.The city-state now has the most infections in Southeast Asia.As a result, Singapore is bringing back some restrictions.Singapore's Ministry of Health said that, as of Monday,about 87 percent of reported cases are workers living in dorms.These kinds of housing can have up to 20 people living in one room.Singapore is known for having a high number of foreign workerswho come from Britain and other places to work in business or banking.But many foreign laborers come as well.They include Philippine cleaners and Bangladeshi building laborers.Migrant workers are part of Singapore's two-track economyof both high-paying technology jobs and low-paying labor jobs.The activist group Transient Workers Count Too said it has been warningthat crowding among migrants presented a risk of viral spread.Alex Au is the group's vice president.He said, "There's no denying now that density and poor ventilation in our dorms" helps spread disease.But he said that is only part of the problem.Au said Singapore is too dependent on low-cost labor.Migrant workers there are getting attention nowbecause they make up a large majority of Singapore's COVID-19 cases.Before the large increase in infections,experts had praised Singapore for its strong actions to limit the spread of the disease.Experts said measures such as fast treatment for patients,following contacts of people who could carry the disease and travel restrictions were successful.Travel restrictions, however, could not prevent the spread of COVID-19 within Singapore.Prime Minister Lee Hsien Loong said the disease was "hidden" as it spread largely among laborers.New cases have increased in the past three weeks after being comparatively low before then.HOME is a non-profit organization in Singapore aimed at helping workers.The group said in a statement: "The COVID-19 pandemichas shown that migrant workers are indispensable" to the operation of the country.Singapore's Manpower Minister Josephine Teo said there is "no question"that Singapore should improve conditions in the dorms.Teo's ministry is helping with providing food and supervising workers at the dorms.But she said Singapore must deal with the virus emergencybefore it can deal with workers' living conditions over the long term.The Health Ministry said it is increasing testing for the virus in the dorms.It is also following possible carriers, a method known as contact tracing.Health Minister Gan Kim Yong spoke Monday about the new measures.He said Singapore had increased health care workersand expanded medical centers in preparation for more cases.Officials are especially concerned about what are called "unlinked" cases.For these cases, it is unclear how the virus spread from one person to the next.Labor activist Au said he hopes the health crisis will bring attention to important labor issueslike high payments to recruiters and unpaid work for migrants.Au said labor unfairness is a "structural problem" that opens the country to many other problems.He added, "It's hard to predict where the next crisis might come from."