Officers said the men targeted the cash machine on Al-Farazdaq Road near Obaid Hospital.
The police said a Saudi in his 30s who was in charge of ATMs at one of the commercial banks informed them that four boxes in the machine containing SR1.08 million had gone missing.
With no lead to start with, the police questioned people who were ex-employees of the bank and officials in charge of ATMs.
The investigations then focused on the six men, five of whom were in charge of loading ATMs and the sixth a former bank employee.
Officers said there was enough evidence to charge the six suspects so they were arrested.
The men opened the ATM after obtaining its security code from one of their accomplices and stole the money, which they then hid in a farm in Al-Kharj belonging to one of their relatives.
The police said SR820,000 was retrieved from the suspects and investigations were continuing.
