The thefts began on last Thursday and had continued up until Wednesday with the filing of another police complaint, the Daily News Online quoted PoL Col Plitthipong Nutchanart, chief of Muang police station, as saying.
The complainant losing the most, at 323,868 baht, was identified as Taweepong Chareonroob, captain of Krabi's provincial football team.
PoL Col Plitthipong said it was believed the gang is from Malaysia and had planned the ATM heists a month earlier.
Warning messages have been posted at ATMs where users had their electronic information stolen, advising cardholders to stay away from the machine. Many cardholders opted to carry out their transactions inside banks instead.
The latest warning was posted at a Krungthai Bank machine in front of the provincial hall, with a message saying: "Do not withdraw money from this machine. I just did it on 13-08-57 at 08:20. The bank then informed me my card had been hacked and used in Taiwan. Best wishes."
Pol Col Plitthipong said investigators had requested footage from security cameras at banks where customer information was stolen, but were told to wait citing "complicated procedures".