By John Geddie and Aradhana Aravindan

SINGAPORE (Reuters) – Singapore said on Tuesday that the number of migrant workers infected with coronavirus in the city-state may be higher than official tallies as symptomatic patients had been isolated in dormitories with mass outbreaks before testing.

The nation of 5.7 million people has nearly 15,000 confirmed coronavirus infections, one of the highest in Asia, largely due to infections in cramped bunk-bed accommodation housing more than 300,000 mostly South Asian workers.

On Tuesday, Singapore reported 528 new infections – its lowest in almost two weeks – but authorities said the real number could be greater due to a lag in testing.

“When we report figures…of confirmed and verified infections, the number of foreign workers that are in the dormitories that we are keeping a close eye on with respiratory symptoms may in fact be bigger than the actual number that we report,” the health ministry’s director of medical services, Kenneth Mak, said at a media briefing.

Mak said any discrepancy in the official numbers would eventually be ironed out as these workers would need to be tested before they could leave isolation and return to work. He declined to say how many workers were in such a position.

“The numbers will reconcile. It’s not an issue of fudging or dodging or trying to hide numbers. It is really to make sure that our priorities in testing match the needs that we have on the ground,” Mak said.

Singapore said it has been scaling up its testing capacity across the island, including in dormitories, from an average of 2,900 tests a day in early April to more than 8,000.

Authorities say they have tested 2,100 people per 100,000, compared with 1,600 per 100,000 in the United States, and 1,000 per 100,000 in Britain.

Amid the surge in cases, the city-state has also been rapidly building bed space for low risk and recovering patients in exhibition halls and other temporary facilities. On Tuesday it said it wants to scale up that capacity from around 18,000 beds currently to more than 40,000 in the coming months.

While the coronavirus has been spreading rapidly in the dormitories, many of which the authorities have sealed off, the spread in the community apart from the migrant workers has been much slower, with an average of 20 new cases a day over the past week.

Fourteen people have died of the coronavirus in Singapore.

(Reporting by John Geddie and Aradhana Aravindan; Editing by Robert Birsel and Angus MacSwan)