Facebook is reportedly running again after some users experienced prolonged issues for much of the morning.

The issues affected people accessing both Facebook and Facebook-owned Instagram from around 6am this morning.

Facebook responded to concerns this morning, saying that some users may encounter challenges accessing the site as it was down for "maintenance".

A link on the social media site explains that the problems will only be encountered by some users because Facebook doesn't do maintenance on the whole site at the same time.

These issues came off the back of users encountering a number of problems yesterday in accessing Google's YouTube, Gmail and Google Drive services.

The outages have affected people in the US, Central and South America and Europe, according to tweets and the outage-tracking site DownDetector.com.

Facebook quashed some early online rumours that the outages were the result of a distributed denial-of-service (DDos) attack — a type of hack in which attackers flood a company's network.

"The issue is not related to a DDoS attack," Facebook said in a tweet.

During the outage social media users took to Twitter to express their frustrations - and to mock Facebook.