Explosions heard in Kent early on Saturday were thought to have been gas canisters used in a cash machine theft.
Police believe thieves used a large digger from a nearby field to take the machines from Sainsbury's, Northfleet.
It is thought they used two cars which were then set alight at about 0600 GMT in Sole Street, Meopham. The scene has since been made safe.
"The explosions were caused by gas canisters which could have been used to open the cash machines," police said.
Investigations were still under way on Saturday afternoon at the scene at Sainsbury's, Northfleet, where officers found a large hole in the wall.
Kent Police say they were called to the supermarket just after 0230 GMT, to find two machines had been taken.
A spokesman said the store was open as normal and appealed to any witnesses to contact the Gravesend crime unit.