Blizzard, the developer behind games like Hearthstone, World of Warcraft and Overwatch, has confirmed it is having issues with its gaming network that players log in to in order to play its games.

Reports of players not being able to log in to surfaced at 2 a.m. EDT on Friday, with most players saying they simply could not access their accounts. Blizzard's customer service has since confirmed the problem.

It is unclear if the problem arose because of a technical issue or if it was caused by a malicious attack. In April, the company said it was battling a distributed denial of service attack that was preventing its customers from playing their games, an attack claimed by the hacking group known as Lizard Squad.

Lizard Squad has previously carried out attacks against World of Warcraft in 2014 and is also credited with attacking both the PlayStation Network and the Xbox Live system.

According to the heat map from DownDetector website, most reports of login failures are coming from North America and Australia.