Thousands of Airbus planes are being returned to normal service after being grounded for hours due to a warning that solar radiation could interfere with onboard flight control computers.

The aerospace giant - based in France - said around 6,000 of its A320 planes had been affected with most requiring a quick software update. Some 900 older planes need a replacement computer.

French Transport Minister Philippe Tabarot said the updates went very smoothly for more than 5,000 planes.

Airbus CEO Guillaume Faury apologized for what he called logistical challenges and delays since Friday, adding that their teams are working around the clock to ensure that updates are being done as swiftly as possible.

In the UK, disruption at airports has been limited, with most airlines reporting that few flights had been affected. However, the impact has varied by region, with some airlines, like Jetstar in Australia, experiencing higher levels of disruption.

Airbus identified these issues after an incident in October involving a JetBlue Airways plane, which highlighted the problem with the aircraft's software that calculates elevation at high altitudes. While around 5,100 aircraft are expected to function normally after software updates, about 900 older planes may be grounded longer due to hardware replacements.