GWENT Police is remaining vigilant after recent metal thefts at gas sites in Caldicot and Caerwent that could have led to 'catastrophic' explosions. Copper wire along earthing cables in the sites has been taken from the sites, with one wrong move having the potential to cause a spark and therefore an explosion. Gwent Police's neighbourhood watch system, Owl, is appealing for anyone with any information, or anyone who sees suspicious behaviour around the plants, to call 101. Two sites in Marshfield, Newport have also been targetted. Owl's warning to members read: "Another in Caerwent and a fourth in Caldicot have been attacked. "This could result in a catastrophic manner. If one wrong cable is cut and causes a spark, the site and everything around it will be blown up, which would result in the next station backing up and blowing up also." Gwent Police farm watch co-ordinator Allan Mills said: "There is always a risk of danger when gas and electricity sites are concerned. "If the wrong wires are cut or sparks are created there is a potential of danger. "There is a very good chance of the perpetrators themselves getting injured in taking the cables." The break-ins are happening during both day and night. No arrests have yet been made, but Gwent police is working with the relevant utility companies on all enquiries.