A major online outage that hit bank and airline websites on both sides of the Pacific was not caused by a cyberattack, the tech provider responsible said Friday.
In a statement, US-based Akamai said around 500 of its customers were briefly knocked offline on Thursday because of a problem with one of its online security products.
The outage hit American, Delta, United and Southwest Airlines and most of Australia's major banks, leaving customers unable to access websites and mobile apps.
Akamai said the problem was resolved in just over four hours, although most websites experienced problems for around an hour.
"The issue was not caused by a system update or a cyberattack," Akamai said, adding the issue had been narrowed down to a data routing problem that had now been fixed.
It is the latest incident to draw attention to the stability of economically vital online platforms and the key role that a handful of little-known "CDN" -- content delivery network -- companies play in keeping the web running.
Last week, US media and government websites, including the White House, New York Times, Reddit and Amazon were temporarily hit after a glitch with cloud computing services provider Fastly.
Fastly offers a service to speed up loading times for websites.
Akamai offers a range of similar IT products designed to boost online performance and security.
The firm said this problem was linked to a product that prevents DDoS attacks -- an often crude cyberattack that knocks websites out by peppering them with requests for data.
"Many of the approximately 500 customers using this service were automatically rerouted, which restored operations within a few minutes," the company said.
"The large majority of the remaining customers manually rerouted shortly thereafter."