"We are currently monitoring a DDOS attack against network providers which is affecting latency/connections to our games," wrote Blizzard in a tweet.
Battle.net runs many of Blizzard's popular games, including Overwatch, World of Warcraft, Hearthstone: Heroes of Warcraft, and more.
Gamers took to social media with frustration, as VentureBeat points out it was the third time Blizzard's servers have gone down in a week.
Poodle Corp, a splinter organization of Lizard Squad that specializes in taking down servers of large companies, is claiming responsibility for the attack. In a tweet, Poodle Corp said it would release Blizzard's servers if 2,000 retweets were met.