The new cases brought the national tally of COVID-19 patients to 1,405.
Two of the new patients arrived on a flight from Myanmar on December 12, while the third one returned from the US transiting Japan on December 6.
Also on December 15, six more COVID-19 patients were given the all clear, raising the total recoveries to 1,252. The fatalities remain at 35.
Among patients still under treatment, three have tested negative for SARS-CoV-2 once, six twice and six thrice.
A total of 18,957 people who had close contact with COVID-19 patients or arrived from pandemic-hit areas are being quarantined nationwide, with 208 at hospitals, 15,688 at concentrated facilities and 3,061 at home or their accommodations.
