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 were 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 Downdetector.
Two hours later, Instagram said the issue on its platform had been fixed.
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.”
Two hours later, it issued an update saying: “Things have been fixed, and everything should be back to normal now.
“Thank you for bearing with us (and for all the memes this week).”
Monday’s outage, which affected Facebook, Instagram and WhatsApp, left billions of the platforms’ users unable to get online for more than five hours.
Facebook, which owns all three platforms, said the glitch was caused by an error during a routine maintenance job and “not by malicious activity”.
The US company has been contacted over the cause of the second outage.