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.

"Fewer than 100 aircraft" still needed the update, Airbus had told him, according to local media.

Airbus CEO Guillaume Faury apologised 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".

On Saturday morning, Air France appeared to be experiencing some disruption, with several flights in and out of Paris's Charles de Gaulle Airport delayed or cancelled.

American Airlines said 340 of its planes were affected and that it expected "some operational delays", but added the vast majority of updates were being completed on Friday or Saturday. Delta Airlines said it believed the impact on its operations would be "limited".

In the UK, disruption at airports has been limited. London's Gatwick Airport reported "some disruption", while Heathrow said it had not experienced any cancellations. Manchester Airport said it did not anticipate significant problems, and Luton Airport said there is "no expected impact".

The UK Civil Aviation Authority said it had worked through the night to carry out the update and that, while some disruption had been anticipated, very few flights had been affected.

British Airways and Air India are understood not to be heavily impacted by the issue.

On Saturday, Easyjet said it had completed the update on a "significant number" of its aircrafts, and plan to operate as normal.

Wizz Air is also running as normal, having rolled out updates overnight.

In Australia, budget airline Jetstar cancelled 90 flights after confirming around a third of its fleet was impacted, with disruption expected to continue all weekend despite the majority of aircraft having already undergone the update.

Air New Zealand had grounded its A320 planes until the update had been completed, with all flights having now resumed.

Airbus discovered the issue after a JetBlue Airways plane flying between the US and Mexico suddenly lost altitude and emergency landed in October. At least 15 people were injured.

The firm identified a problem with the aircraft's computing software which calculates a plane's elevation, and found that at high altitudes, data could be corrupted by intense radiation released periodically by the Sun.

As well as the A320, the company's best-selling aircraft, the A318, A319 and the A321 models were also impacted.

While approximately 5,100 of the planes could see their issues resolved with the simple software update, for around 900 older planes, a replacement computer would be needed.

These planes would need to be grounded until resolved.

The length of time that takes will depend on the availability of replacement computers.