Facebook and its WhatsApp and Instagram apps have suffered an outage affecting tens of thousands of users.

Users of the social media sites around the world appeared to be affected. Facebook said it was aware that some people were having trouble accessing company's apps and products.

Instagram, owned by Facebook, also stopped working and the company tweeted it was aware users were having issues.

The companies have not given a reason for the outages however an error message on Facebook's webpage suggested a Domain Name System error, Reuters reported.

A similar outage at cloud company Akamai Technologies Inc took down multiple websites in July.

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. The outage might be affecting a larger number of users.

Facebook's instant messaging platform WhatsApp was also down for over 35,000 users, while Messenger was down for nearly 9800 users.

Facebook has experienced similar widespread outages with its suite of apps this year in March and July.

Several users using their Facebook credentials to log in to third-party apps such as Pokemon Go and Match Masters were also facing issues.

Facebook shares fell 5.5 percent in afternoon trading on Monday, inching towards its worst day in nearly a year.

In recent months many high-profile denial of service attacks have hit companies worldwide including banks and government agency sites in New Zealand.