A man accidentally blowing himself up while allegedly trying to rob an ATM machine.
The incident happened on Thursday night outside a row of shops on Glasgow Road, Clydebank.
CCTV footage showed a man flying backwards from the force of the blast and then collapsing on the ground.
Debris from the cash point was said to be scattered as far as 25 yards away from the blast, while nearby shop windows also suffered damage.
A 51-year-old man was found at the scene and taken to the Queen Elizabeth University Hospital where he remains in critical condition.
Police believe the men may have been attempting to steal the ATM at the time.
Speaking after the explosion, detective inspector Fiona Macarthur said: “Inquiries are at a very early stage to establish the full circumstances and officers are currently examining CCTV as well as speaking to local businesses and residents.
“One line of enquiry is that two men were attempting to steal the ATM and one of them has been injured in the process.
“I would appeal to anyone who was in the area late last night and saw or heard anything suspicious to please get in touch.”
Police say a 48-year-old man has been arrested and is being held in police custody in connection with the incident, which happened at an ATM outside Premier Stores.