Some of the world’s biggest companies’ web pages were affected by a major website outage on Thursday.

The website Downdetector showed sites belonging to retailers, banks, airlines and gaming services across the UK, US and other countries were knocked offline.

Around 30,000 companies including Amazon, McDonald’s, Airbnb and PlayStation were among those that suffered the outage for about 40 minutes before coming online again.

Many of those affected took to social media sites to apologise and reassure customers.

Airbnb said it was investigating the cause of the incident in a post on Twitter.

US airline Delta said its website and app were working normally after being “briefly affected Thursday by a technical issue … that affected websites globally”. Customers had reported being unable to check in for flights during the outage.

During the outage, which began on Thursday afternoon, websites did not load and displayed Domain Name System (DNS) service errors.

DNS, or Domain Name System, is a service that translates readable domain names into machine-readable IP addresses, connecting it to a server and delivering the requested page on the user’s phone or laptop.

Akamai which provides the service to thousands of companies, said it was “aware of an emerging issue” with its Edge DNS service and urged customers to contact their technical support service. The company has not confirmed whether it was the source of the issue.

The service provider later said it had applied a fix for the problem and service was resuming. Its website said all systems were operational as of Thursday evening and the incident had been “mitigated”.

After the outage ended, the company confirmed “a software configuration update triggered a bug in the DNS system, the system that directs browsers to websites”.

“This caused a disruption impacting availability of some customer websites,” it said in a post.

Rolling back the software update fixed the problem, Akamai said, apologising for the trouble.

Database management company Oracle also pointed to an issue with Akamai’s services.

“We are monitoring a global issue related to Akamai Edge DNS that is affecting access to many internet resources, including Oracle cloud properties. Resources within the Oracle cloud are continuing to run and are not affected by this event,” a company statement read.

The internet was hit by another major outage about a month ago when Cloud service company Fastly encountered an internal error. Websites like Amazon, Reddit and The Guardian were inaccessible for around an hour.

This issue was caused by a customer changing their settings, creating an internal bug in Fastly’s systems, the company said.