Charity warns parents the game's basic safety standards have been overlooked as reports of people being lured to a sex shop emerge

Children who play the latest Pokémon game are in danger of being preyed on by adults who wish to exploit them, according to a national children’s charity.

In an open letter to computer games company Nintendo UK, the chief executive of the NSPCC, Peter Wanless, claimed the smartphone app game, which has become an overnight sensation, has overlooked its basic safety standards.

He says Pokémon GO appears susceptible to being hijacked by users who wish to harm other players and as such raises fundamental child safety concerns.

The game which involves users walking around their neighbourhood and looking for characters, locations and other users via their smartphone (pictured) was only launched in the UK on Thursday but is said to already have more daily users than Twitter such is its popularity.

In his letter, which was issued before the game was even officially available in the UK, Wanless said he has heard of users being lured in dangerous situations because of its geo-location feature.

The children’s charity chief highlighted reports that armed robbers lured teenagers in Missouri to a particular spot using the game and in Devon players are taken to a sex shop.

"I am writing regarding the troubling reports concerning your new app, Pokémon Go, which appears susceptible to being hijacked by users who wish to harm other players and as such raises fundamental child safety concerns," he said.

"Within days of your product launching, there have been numerous accounts of children being placed in dangerous situations."

He continued: "It is well documented that the internet provides a gateway for adults who would wish to exploit and prey on children and apps without appropriate safety features inbuilt into the design help them in this.

"Given Pokémon’s already massive popularity with children, the NSPCC is concerned that basic safety standards appear to have been overlooked.

“I urge you to urgently reassess your app and its security and safety features. We all have a responsibility to ensure that children are protected and as creators of a game with substantive reach, you have a weighty responsibility to protect your young users.”

The initial launch of the game in the UK was delayed after its popularity in the US crashed the game’s servers.

There have been a number of comments around the world over the game's safety, including warnings that people are putting themselves in danger simply by not looking up from their smartphones when crossing the road.

As well as the letter to Nintendo, the NSPCC has created a parent’s guide including tips and advice for keeping children safe while playing the game.

The guide includes an explanation of the game as well as outlining what it perceives to be the main risks.

Nintendo UK has been asked for comment.