Police are urging residents not to be taken in by 'fake news', after a series of scam stories regarding an assault in Knighton began circulating on social media.

Dyfed Powys Police issued a statement on Wednesday regarding the stories, which describe an attack on "Emily Williams from Knighton" which did not occur, advising people to be wary of the ruse.

The stories, which circulated on social networking site Facebook last week, described a fabricated assault on an older lady who was supposedly attacked on her way to the car after visiting a shop.

The scheme appeared to be attempting to dupe users into purchasing a personal safety alarm, although Police say even this may be a scam to harvest people's credit card details.

A Dyfed-Powys spokeswoman said: "We have been made aware of an article being circulated on social media about a woman who was assaulted in Knighton, Powys. This incident did not occur.

"Please be aware that if these news stories pop up in your newsfeed, they are a scam. No such incident has occurred in Knighton, Powys, so please do not be alarmed.

"Also, don’t be tempted to click on the links to the highlighted safety products. Protect your personal details online; stay safe and secure.

"If you have been scammed, or would like advice on how to stay safe, call us on 101, email contactcentre@dyfed-powys.pnn.police.uk or get more information from Action Fraud and Get Safe Online."

Earlier this week Facebook's Mark Zuckerberg apologised to a United States government committee for his company's failure to stamp out fake news stories on the social media platform.

The Facebook CEO is facing a grilling from US lawmakers over the Cambridge Analytica scandal, in which the British research firm hired by the Donald Trump campaign improperly obtained data from 87 million Facebook users.

"It’s clear now that we didn’t do enough to prevent these tools from being used for harm," Zuckerberg said at a joint hearing of the Senate Judiciary and Commerce committees.

"That goes for fake news, foreign interference in elections, and hate speech, as well as developers and data privacy. We didn’t take a broad enough view of our responsibility, and that was a big mistake.

"It was my mistake, and I’m sorry. I started Facebook, I run it, and I’m responsible for what happens here."