Police are investigating a break-in at NatWest Bank in Market Hill, Buckingham.
Insp Emma Garside told the Advertiser: “In the early hours of the morning there was a break-in and there is an active investigation ongoing.”
Insp Garside said it appeared the break-in happened at about 4.45am, and there are witnesses who believe they saw the offenders leaving the scene.
She said: “It looks like the ATM was attached from the inside. We’re not sure yet how much money has gone.”
Scenes Of Crime officers are attending the scene and CID officers will be making enquiries in the town.
CCTV footage from local cameras will be reviewed.