Pokemon monsters have been spotted on the streets of Doncaster as a new global gaming craze grips the town.
Pokemon Go, a mobile game that has become a worldwide phenomenon, has been released in the UK - and gamers have already begun spotting the game's virtual reality creatures at locations all over Doncaster.
Twitter users have been posted their discoveries online while a Facebook group, Pokemon Go Doncaster, has already attracted nearly 500 people.
The game, which lets players roam a map using their phone's GPS location to find and catch Pokemon characters to train and battle, has already become a smash in the USA, Australia and Germany.
The game has added millions to the value of Nintendo, which part-owns the franchise and players around the world have been gripped by the gaming sensation.
Demand for the app is so high that new account registrations are periodically unavailable and servers have been crashing under the weight of demand to play the game.
The game uses a smartphone's GPS location and real-world maps to track players as they move around. Players can visit Pokestops - typically landmarks or buildings - and collect free items in the game.
Doncaster Twitter user Lee Piekarski is among those gripped by the game and tweeted: "Doing well I got a pikachu #PokemonGO #PokemonGOuk." He later tweeted: "Found this one at the lakeside in Doncaster lol #PokemonGO #PokemonGOuk," with a picture of snake like creature called Dratini attached, posing by the lake.
The main aim is to catch Pokemon, which pop up along the way. The game provides an augmented reality experience, using the smartphone's camera to provide a live view of the world, with Pokemon superimposed.
Any creatures caught can be used in battle against other players at Pokemon gyms - also real-world landmarks.
However, some people have raised concerns about the app's safety. The chief executive of children's charity NSPCC urged the app's makers to adapt the game before its UK release, warning that adults could use it to prey on children.
An NSPCC spokesman said: "It's deeply troubling that the app's owners have ignored many warning signals and well documented child safety concerns. It would have been better if they had taken time to reflect on these and put their young users first."
The makers of the game - Niantic and The Pokemon Company - said in a statement: "We take player safety seriously and want everybody to have a fantastic time exploring while safely playing Pokemon Go.
"We encourage all people to be aware of their surroundings and to play with friends or family, especially when you're exploring unfamiliar places. Please remember to be safe and alert at all times, don't drive and play, abide by local laws, and respect the locations you visit and people you meet during your exploration."
the app has already thrown up a series of weird and wonderful news stories. An American woman found a dead body while she was looking for a Pokemon in a river near her home.
And four people were arrested after they used the game to lure players to remote places and then rob them at gunpoint.
The monsters in the game were first popular in the 1990s when they started on the Nintendo Game Boy. Trading cards became a huge hit in school playgrounds and the product's slogan "gotta catch 'em all" became a global hit.