Facebook Inc's (FB.O) social media website was inaccessible for some users on Monday afternoon, its second outage in less than a week, Reuters reported.
The company's shares were down nearly 4 percent at $89.25 in afternoon trading.
Facebook's map on Downdetector.com, which monitors disruptions, showed major outages over parts of North America.
The social network's mobile app appears to be down as well, but Messenger services appear to be working.
A message displayed on facebook.com said "sorry, something went wrong. We're working on it and we'll get it fixed as soon as we can."
Facebook suffered a similar outage on Thursday when it was down in North America, Europe, Australia and India.
Facebook could not be immediately reached for comment.