Crooks stole £8,000 worth of diesel from a petrol station in a brazen two-hour raid.
They are believed to have used specialist tools to pump the fuel from an underground tank at the Coventry Hill Service Station, in Lower Road, Hullbridge in the small hours of this morning.
Shocked staff who opened the service station at 8am found that the thieves had taken away 5,600 litres of the fuel.
The crooks are believed to have parked a Luton van on the forecourt for about two hours and pumped the diesel into the back of their vehicle.
Police have now told other Hullbridge service stations to double check their security measures in the wake of the incident.
Ahren Perry, the officer investigating, said: "Lower Road is a busy road and we know that many vehicles would have driven past during the two hours the thieves were on the site.
“We also know that a number of pedestrians walked past. We want to hear from anyone who has information about the van and the two men.”
Anyone with information is asked to call 101.