Gas canisters used in Tring cash machine raid
Gas cylinders have been used by raiders to try to blow open a cash machine at a bank.
The machine was badly damaged and windows were smashed during the attack at Barclays Bank in Tring High Street, Hertfordshire.
Police and fire officers were called to the scene at about 04:20 GMT after reports of an explosion.
Four men were seen getting into a black car. It is not yet known if anything was taken, said police.
The road outside has been cordoned off while scenes-of-crimes officers inspect the area.
A neighbouring shop owner said: "It is very scary to think of the damage that could have been caused."