Two teenagers stole a mobile phone after the owner agreed to meet them in the street, sparking a renewed police warning.
The victim had advertised a mobile phone for sale on Gumtree, an online selling site, before agreeing to meet a buyer at Three Cherry Trees Lane, Hemel Hempstead, on Thursday, March 10.
On arrival, the seller was met by two men, one of which has asked to see the phone.
The victim handed it over, before both men have ran off with the phone without paying.
The offenders are described both as white men of slim build.
The first man was in his 20s, around 5ft 8in tall, with ginger hair, freckles and an Irish accent. He was wearing a navy hooded top and light-coloured jeans.
The second male was aged in his late teens, around 5ft 6in tall and wearing a black Adidas tracksuit.
In a similar incident on Monday, February 22, a seller has agreed to meet a buyer at Hunters Oak in Hemel Hempstead after placing an advert online.
On arrival, the buyer has walked off with the for sale items, which were a number of DeWalt power tools.
The seller followed the offender and challenged the man, who punched the seller before running off.
One of the items was retrieved by the seller, but the offenders made off with the rest.
These thefts are two of five that have happened since Herts Police issued a warning about the dangers of advertising goods and selling them online.
In January, officers issued a warning after four robberies and eight thefts had occurred since September last year.
The pattern of offences seemed to be that sellers advertising their items online would arrange to meet a buyer in a particular place to hand over the goods in return for cash.
On arrival, the buyer would take the goods with no payment given and in some cases threats made towards the seller.
Items being sold included animals, electrical items, baby goods and furniture.
DC Yolanda Morales-Willis, from the Hemel Hempstead Local Crime Unit, said: “While most people who use websites like Gumtree do so with honest intentions, people selling items online should still exercise caution when agreeing to meet people to make transactions, particularly if the buyer offers money to them to deliver the goods.
“Always choose a location that you know; preferably a busy public place and that you know is covered by CCTV, such as a supermarket or shopping centre car park. If you notice anything suspicious, do not continue with the transaction.”
Anyone with information should contact DC Morales-Willis on the Hertfordshire Constabulary non-emergency number 101.
Alternatively, call Crimestoppers anonymously on 0800 555 111 or use their Anonymous Online Form at www.crimestoppers-uk.org.
No personal details are taken, information cannot be traced or recorded and you will never need to go to court.