New cases of coronavirus disease - quarantined arrivals from India, Kuwait and South Sudan - include one person who was previously diagnosed with the illness.
The Centre for Covid-19 Situation Administration said three of the five had returned from India.
One is an Indian man, 31, who has work permit in Thailand. He arrived on Sept 23 on the same flight as six previously confirmed cases.
Two other arrivals from India are Thai men aged 26 and 64. They returned last Friday on the same flight as a previously confirmed case.
The new case who had earlier been found infected with Covid-19 is a Thai male worker, 41, who arrived from Kuwait on Sept 22.
He had left for Kuwait in January to work at a gas refinery. He had stayed at a workers' camp with many Covid-infected people.
The man had been diagnosed with Covid-19 between June and July and isolated for 14 days at a place prepared by his employer. He had tested negative for Covid-19 before his return.
The other new case, a Thai army engineer, arrived from South Sudan on Sept 22 on the same flight as 23 previously confirmed cases.
All new cases were asymptomatic.
Total cases rose to 3,564, of whom 3,374 (94.6%) have recovered and 131 others remain at hospitals. The death toll is unchanged at 59.
