Merseyside police are urging people in a certain area of Merseyside to be vigilant when answering their doors.
Officers investigating the crimes are issuing a reminder to residents in Norris Green to take certain steps to prevent them becoming the victim.
The warning comes after detectives received reports of three men in a white van approaching addresses on Delabole Road.
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The men were claiming to be from Cobalt Housing and offering to carry out gardening work for cash.
A further report, on Sunday, November 19, was a man offering gardening work to a woman on Meyrick Road.
He cut down her tree then drove her to a cash point and made her withdraw £1,800 and left her stranded.
Enquiries are ongoing into all of the reported incidents and officers have listed a number of steps people can take to help stop it happening to them.
The steps include not keeping a lot of cash at home, not opening your door if you're unsure who the caller is, never letting people in your property if you don't know them and asking to see identification.
Residents should also always keep the key chain on the door and be wary of distraction tactics including people asking for a drink or water or using the toilet.
Detective Sergeant Richie Shillito said: "Suck deception and intimidation is appalling and we're determined to find the people responsible and bring them to justice.
"If you live in the Norris Green area and have seen or been made aware of any similar approaches recently, please pass on any descriptions, vehicles, CCTV or other information to us and we will do the rest.
"These types of despicable offenders prey on the most vulnerable members of society and often leave a profound and lasting impact on their victims.
"They may claim that work needs doing on a property which is not even required, and charge an extortionate amount of money to carry out any work, which often does not even get carried out.
"Elderly people, their relatives and friends should always be wary of callers to their address offering any kind of service, however official they may appear.
"Identification should always be asked for and produced and, if necessary, contact made with the company they claim to work for to verify identities."
