Burglars target homes marked with stickers by scouts who check streets for easy targets Plastic stickers placed by burglars on properties in Wandsworth, London '24/7 Locksmith' stickers have already been linked to one local burglary Scouts find vulnerable homes before calling to see if people are at home By Mark Duell and Sara Smyth Burglars are marking houses as targets for break-ins with small, transparent stickers advertising a locksmith. The signs, which purport to offer a "24-hour service" but include a fake phone number, are typically placed by letterboxes. Police in London have already linked one burglary to the stickers. They have received dozens of complaints from residents across the capital who have found them on their doors. Scam: The stickers - which have already been linked to one local burglary - are printed with the words '24/7 Locksmith - Repair Installation Locked out' and a fake telephone number of 0203 582 8175 Officers believe that "scouts" place the stickers on properties they deem to be vulnerable, after checking whether the owners are at home during the day and if windows and doors are locked. It is thought the stickers were designed so that if a scout is apprehended while marking a house, they can claim they are simply handing out advertising material. A spokesman for Wandsworth Council in south-west London said: "These stickers are clearly not for advertising purposes. They're not going next to the lock where you may notice them and the phone number has never existed. They're difficult to spot unless you're on the lookout. Inspector David Bannister from Wandsworth police added: "At this time of year with the darker evenings there is traditionally a rise in burglaries, particularly between 3pm and 7pm. There have been a number of front doors found with stickers, giving details of a locksmith, which enquires reveal is not a genuine company. Targets: The virtually-transparent plastic stickers are being placed by burglars on vulnerable properties in Wandsworth, south-west London (file picture) It is assessed that these markers are being used by potential burglars to mark potential targets which are then returned to subsequently. If you find a sticker on your door, the best thing to do is remove it. Cllr Jonathan Cook, the council's crime prevention spokesman, said: "There is growing evidence that some organised teams of burglars may be using this method to target homes in South London. We are urging local residents to keep a very close eye out for these stickers and if they find one to remove it straight away Cllr Jonathan Cook, Wandsworth Council We are therefore urging local residents to keep a very close eye out for these stickers and if they find one to remove it straight away. It also goes without saying that if people can beef up their home security by fitting sturdy locks to doors and windows and alarms, then this will always reduce the chances of them falling victim to thieves and burglars. These are placed near the main lock. The council later said that police had received "lots of new intelligence" after a warning was issued to residents - and are now following up a number of new leads to catch those who are responsible. Burglars have been using coded chalk symbols to let other criminals know whether a property is worth targeting, MailOnline reported in September. The marks, dubbed the Da Pinci Code, are made by would-be thieves to indicate if the house is vulnerable, revealing who is living in the house and whether there is anything worth stealing. Chillingly, one sign in Walkden, Greater Manchester, in the shape of an open book, said a vulnerable female resident is the occupant and another symbol indicated a 'nervous' homeowner. Code: Would-be criminals scrawl the markings on properties to indicate whether the house is worth targeting