Facebook and Instagram users have been unable to access services for the second time in a week.
The social media giants have apologised to users who are unable to refresh their home pages, though the outage appears to be less widespread than on Monday.
Around 2,000 people reported being unable to access Facebook at around 8pm on Friday, according to the outage tracking website Downdetector.
Facebook said on Twitter: “We’re aware that some people are having trouble accessing our apps and products.
“We’re working to get things back to normal as quickly as possible and we apologize for any inconvenience.”
Instagram added: “We know some of you may be having some issues using Instagram right now.
“We’re so sorry and are working as quickly as possible to fix.”
Monday’s outage, which affected Facebook, Instagram and WhatsApp, left billions of the platforms’ users unable to get online for almost six hours.
Facebook, which owns all three service, said the glitch was caused by an error during a routine maintenance job and “not by malicious activity”.