Facebook Inc has said it is working to restore access to its social media platforms, including photo-sharing platform Instagram and messaging app WhatsApp, after an apparent global outage.

The platforms were down for tens of thousands of users on Monday, according to outage tracking website Downdetector.com.

The website was showing outages in heavily populated areas like Washington, DC, and Paris, with problems being reported from about 15:45 GMT.

“We’re aware that some people are having trouble accessing our apps and products,” Facebook said on Twitter. “We’re working to get things back to normal as quickly as possible, and we apologize for any inconvenience.”

A similar message confirming the outage also was posted on WhatsApp’s Twitter account.

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.

— Facebook (@Facebook) October 4, 2021

The error message appearing on Facebook.com read: “Sorry, something went wrong. We’re working on it and we’ll get it fixed as soon as we can.”

Al Jazeera could not immediately confirm what was affecting the platforms.

Facebook did not immediately respond to requests for comment from the Reuters and AFP news agencies on the outage.

WhatsApp was down for more than 35,000 users, Reuters reported. Facebook Messengers was also down for nearly 9,800 users, according to the news agency.

Al Jazeera’s Alan Fisher, reporting from Washington, DC, said users in the US, Europe, Africa and the Middle East have reported outages.

“This seems like a global outage, and it’s already gone on a lot longer than the 2019 shutdown which lasted for about an hour, which was caused by technical problems, according to WhatsApp then,” Fisher said.

“This is obviously very concerning,” he said, pointing out that it remains unclear what has caused the outage.

The error message on Facebook’s webpage suggested a Domain Name System (DNS) error, Reuters reported.

Downdetector, which only tracks outages by collating status reports from a series of sources, including user-submitted errors on its platform, showed there were more than 50,000 incidents of people reporting issues with Facebook and Instagram.

But the outage might be affecting more users.

Ian Sherr, editor-at-large at CNET, told Al Jazeera that judging by early reporting on the outage and the error messages users received on Monday, it appears most likely that “something is configured incorrectly”.

“My bet is that someone pushed a button wrong, or a cord got unplugged, which seems very minor but the reality is that we’ve seen these things before where suddenly something is configured incorrectly and entire swaths of the internet are not available,” Sherr said.