PlayStation Network is offline in North America, a day ahead of announced scheduled maintenance. A hacker group on Twitter is claiming its attack took the service offline.

Update: The same hacking group claiming responsibility also Tweeted a bomb threat at an American Airlines flight carrying John Smedley, the president of Sony Online Entertainment. It was diverted to Phoenix from its route into San Diego.

Users who try to log in to PSN or the PlayStation Store on their PlayStation 3 or PlayStation 4 consoles are given a message that PSN is down for maintenance. Sony announced Thursday that PSN would be offline for routine maintenance from noon to about 7:30 p.m. ET on Monday.

Shacknews reported that the same hacker group claimed it was able to take down servers for Blizzard Entertainment, as well as League of Legends and Path of Exile. This is unconfirmed. Blizzard's Battle.net is up as of publication time.

Polygon has reached out to representatives of Sony Computer Entertainment America to ask for more information about today's outage.

Update: The official Twitter account for PlayStation support has told users it is "working to fix the issue as soon as possible," but that it has "no time frame" for when service will be restored.

Update: Sony, through the PlayStation blog, confirmed the outage and indicated it is due to a denial-of-service attack. As of 6 p.m., PlayStation Network remains offline.

Here is the full statement: