Thai locals are screened for signs of the coronavirus at a night market in Chiang Mai province on September 6.
Health officials have repeated calls for people to wear masks and follow social distancing measures after the country's first local transmission of Covid-19 for more than 100 days was recorded last week.
The infected patient, a nightclub DJ who was jailed for alleged drugs offences, tested positive while being held in prison.
Residents must wear masks in public places, use the government's smartphone tracking app and sanitise their hands.
Tourists remain banned from the country amid fears that international visitors could cause a Covid-19 spike.
