Facebook has identified the cause of outages that left some users in the United States unable to post photos or answer messages on Facebook or Instagram during part of Thanksgiving holiday Thursday.
In a statement Thursday afternoon, a Facebook spokesperson told CNN Business that "an issue in one of our central software systems caused many people to have trouble accessing Facebook's family of apps. We quickly investigated, started restoring access, and we're now monitoring for full recovery. We're sorry for the inconvenience."
There were thousands of complaints about both social networks being down as of 10:30 a.m. ET, according to the tracking site Down Detector.
Parts of Instagram appeared to be affected, including the news feed being slow to refresh and trouble uploading pictures. The outage on Instagram sparked complaints on Twitter.
The two services are prone to frequent outages but Thursday's is especially problematic because people love sharing their holiday festivities.
In July, Facebook, Instagram and WhatsApp were all down for nearly a day. The lengthy disruption likely upset advertisers that spend large amounts of money to reach potential customers on Facebook platforms. The company's flagship social network has more than 2.3 billion users, and Instagram has more than 1 billion.
WhatsApp doesn't appear to be impacted by Thursday's outage.