Facebook and Instagram went offline because of Lizard Squad hackers, CBS said on Tuesday.
"Facebook, Instagram, Tinder, AIM, Hipchat öffline #LizardSquad", Lizard Squad tweeted.
Facebook and Instagram failed on Tuesday morning. Facebook website was out of service while Messenger and Instagram could not be updated. Access to services was restored by 10 am Moscow time.
Lizard Squad earlier assumed responsibility for cyber-attacks against Xbox and PlayStation online applications.
Facebook press service has not yet returned a comment on causes of going offline.
Facebook is the largest social network across the globe with $216 billion capitalization (NASDAQ). Its monthly audience is up to 1.19 billion users. 2013 year revenues totaled $7.87 billion, while the net income was $1.5 billion.