Thailand reported nine new coronavirus cases on Sunday, raising the total to 3,291.
Three new cases were Thais returning from Indonesia, two from Singapore, and one each from the Philippines, Bahrain, Egypt and Saudi Arabia.
The Centre for Covid-19 Administration said one male and two female returnees from Indonesia arrived in Thailand on Monday and tested positive for the virus from quarantine in Chon Buri on Friday.
Two Thai men who returned from Singapore and one man from Eqypt tested positive for the virus upon arrival in Thailand on Friday.
One Thai student from the Philippines returned to Bangkok on July 12 and was found infected with the virus during state quarantine in the capital on Thursday.
A Thai woman who arrived from Bahrain on July 19 tested positive on Friday while quarantined in Chon Buri.
A man who returned to Thailand from Saudi Arabia on Saturday tested positive on arrival.
The centre did not provide details on airports.
Thailand now has recorded no locally-transmitted infections for 62 days.
