Detectives have released an e-fit of the doorstep conmen who have been targeting vulnerable people in Brighton, Peacehaven and across Sussex.
The bogus callers have been fraudulently claiming to be from the gas board.
They have been knocking on doors across the area telling those who answer that there has been a gas explosion and the water needs to be checked for contamination.
While one man distracts the owners, the other ransacks the house for cash and valuable items.
One of the men called at the home of an 87-year-old woman in Stanstead Crescent, Woodingdean, at about 4.45pm on Monday 23 May.
Nothing is believed to have been taken.
An hour later two men called on a 61-year-old woman in Arundel Road, Peacehaven, and are also believed to have left empty-handed.
Elsewhere they have stolen cash and valuables.
Detective Sergeant Andy Harbour said: “Sussex Police is committed to catching these criminals who have deliberately set out to steal from the most vulnerable members of our community.
“As part of the investigation detectives are releasing e-fits of the suspects.
“If you recognise these men or believe you may have been targeted by them please contact police immediately.
“The elderly are deliberately targeted due to their vulnerability, which is why it is so important to ‘stop, chain and check’ when answering the front door.
“I’d urge people to get into the habit of taking the time to use the door chain and thoroughly read and verify the identification of every unknown caller before releasing the chain and letting them in.
“Remember, a genuine caller will always be happy to wait.”
The suspect from the Brighton burglary is described as white, aged in his thirties, 5ft 6in tall, slim and with short black hair, possibly gelled.
He was wearing a long-sleeved smart white shirt with the cuffs done up, a black or brown waistcoat over the top, buttoned up, black or brown smart trousers and smart shoes.
The first suspect from the Peacehaven burglary is described as white, aged 30 to 40 years old, slim, 5ft 8in tall and with dark hair.
He was wearing dark, navy coloured clothing.
The second suspect was described as white, aged in his forties, of a slightly sturdier build and taller, with dark hair and wearing a maroon coloured T-shirt.
Police said that they were conducting house-to-house inquiries and forensic examinations.
Anyone with information is asked to contact Sussex Police on 0845 6070999 or the independent charity Crimestoppers anonymously on 0800 555111.