Thieves are siphoning petrol from parked cars while their owners sleep.

Police say petrol thieves have struck across several areas of Sunbury since April 24.

They are targeting cars parked on the side of the road and in driveways overnight.

Hume crime prevention officer Damien Collins said police were casting a wide net in their investigations.

“We haven’t isolated [investigations] of the thefts to a specific area. With these types of cases, sometimes it wasn’t found out until later that petrol had been siphoned from the cars.[It’s only] when they had been driven a bit and the drivers realised that there was no petrol,” he said.

“I would recommend that if people can’t park in a garage, then they should park their vehicles in well-lit areas or secure their vehicles.”

Senior-Constable Collins said that while siphoning was not common in the area, public assistance was needed in nabbing the thieves. “The more eyes out in the community, the better,” he said.

Residents are offering information on the Eyewatch – Hume Police Service Area Facebook page. One poster commented: “A mate of mine had his fuel stolen in Balmoral Court in Sunbury, they left fuel all around the car.”

Another resident said petrol was being siphoned in Goonawarra.

Senior-Constable Collins appealed for the public to report any suspicious activity or vehicles.

Witnesses or anyone with information can contact Crime Stoppers 1800 333 000 or www.crimestoppers.com.au.