Facebook said it, Instagram and WhatsApp were "coming back online" after a massive outage Monday knocked out service to the social media giants for users around the world for more than six hours.

All three platforms, owned and operated by Facebook Inc., based in Menlo Park, California, went out of service at 11:39 a.m. ET. By around 6 p.m. ET, users of all three platforms reported that some service had been restored, but full functionality remained elusive well into Monday evening.