The government reported five new cases of the novel coronavirus on Sunday, all of them in quarantine.
That raises the total in Thailand to 3,190 since January. The death toll remains 58, and 3,071 have recovered, including five over the past 24 hours. Sixty-one remain hospitalised.
Two of the new patients in state quarantine had returned from Kuwait and one each from the United States, India and Japan, the Centre for Covid-19 Situation Administration announced on its Facebook page.
The person who returned from Japan was tested on Thursday, and the others on Friday. None of them showed symptoms of the disease.
Thailand is currently on a four-day holiday for government offices and state enterprise agencies.
The centre is concerned that local transmissions of Covid-19 could return with the mass exodus of people from Bangkok to their home provinces to celebrate Buddhist Lent Day.