A hacking group has claimed responsbility for taking down the Pokémon Go servers using a DDOS attack.
A cyber collective known as PoodleCorp announced on Twitter it was behind the action, but this claim is yet to be verified.
The account also retweeted a post by a user claiming to be the leader of PoodleCorp.
"Just was a lil test, we will do something on a larger scale soon," said the post by user XO.
PoodleCorp has recently targeted high profile YouTubers such as Pewdiepie, according to Gearnuke.
A DDOS, or Distributed Denial of Service, is a way troublemakers crash servers by flooding them with so many requests every second that they cannot cope.
On Saturday, users across the US and Europe complained they were unable to access the game, or that it was freezing.
The best of Pokémon Go on social media
When news spread of the attack, players took to social media to voice their outrage.
Pokémon Go servers also crashed earlier in July soon after launching, due to unprecedented demand.
The incident is one of many international news stories relating to the game since its launch earlier in July.
A man crashed his car into a tree in New York on Friday, later admitting to police he had been distracted by the game.
On Thursday two men in San Diego fell off a cliff after they climbed over a fence in an attempt to catch the animated characters.