Fans of the gaming phenomenon Pokemon Go were in despair today when its servers appeared to have crashed.

The craze, an augmented reality game which has exploded in popularity, uses the phone's GPS location data to allow players to roam the real world and catch virtual monsters.

But it would appear that the creatures were able to roam free this afternoon as fans posted on social media about how the server was down. A hacking group named PoodleCorp has claimed responsibility for taking down the Pokemon Go servers through a denial of service attack.

Pokemon Go has sparked controversy since its launch in the UK on Thursday.

Three students were robbed at knifepoint of their mobile phones while playing the game in Hulme, Manchester, on Friday night just hours after Greater Manchester Police warned of the dangers of using the app.

The force had said it was concerned that the app could provide another online avenue for criminals to exploit.

Elsewhere, four teenagers had to be rescued after getting lost in a mine complex for about six hours while hunting for creatures.

The boys, thought to be aged around 14 or 15, were only saved when they eventually managed to contact Dorset and Wiltshire Fire and Rescue from the bottom of a 100ft ventilation shaft at Box Mine, in Wiltshire.