The domestic case was reportedly a Thai woman, 29, who had come back from Myanmar. Her case was found in Chiang Mai province, and the infected person is currently being treated in Nakornping Hospital in the province. She had suspected symptoms such as anosmia, headache and diarrhoea, since November 23.
The other cases in quarantine included an Indian man, 27, and Indian woman, 31, who were both asymptomatic, and two Thai men, aged 24 and 34, who had returned from the Philippines and Sweden.
The total number of confirmed cases in Thailand has risen to 3,966 (1,004 in state quarantine), 111 are in hospital, 3,798 have recovered and been discharged and 60 people have died.
According to Worldometer, as of 10am on Friday, the total number of confirmed cases worldwide since the outbreak rose to 61.98 million (up by 612,825), 42.78 million have recovered, 19.2 million are active cases (105,224 in severe condition) and 1.44 million have died (up by 10,814).
Thailand ranks 151st for most cases in the world, while the US tops the list with 13.45 million, followed by India 9.35 million, Brazil 6.23 million, Russia 2.21 million and France 2.19 million.