'System failure' grounds United Airlines flights

United Airlines customers were left frustrated this morning after a "system failure" caused serious delays to flights.

Passengers were unable to disembark their planes for over an hour and some were left waiting to board for up to five hours, according to several angry tweets.

United, the third largest airline in the world, took to Twitter at 7.30am UK to announce that it was aware of the problem and was working to fix it, before announcing at 8.15am that it was resolved, however it appears that the delays had started long before.

Rumours began to circulate that the global meltdown was as a result of a concerted cyber attack, however IT Pro has been unable to verify these claims at the time of publication.

In a statement to IT Pro, a United spokesman said: "Earlier tonight we experienced a system issue causing some flights delays. As of 3am ET we have resolved that issue and these flights are resuming. We apologize for the inconvenience."

IT Pro also asked for further details on the cause and scale of the disruption, but did not receive an answer. However, flight safety is not thought to have been compromised.

While concerns of data breaches often circle around any large scale disruption such as this, sometimes the answer is more innocent. Last year, flights to and from Paris-Orly airport were brought to a standstill not by hackers, but by a Windows 3.1 error.