A cyberattack at a provider of check-in and boarding systems has disrupted operations at several major European airports, including London's Heathrow, the continent's busiest, causing flight delays and cancellations on Saturday.

Collins Aerospace, which provides check-in and boarding systems for several airlines across multiple airports globally, is experiencing a technical issue that may cause delays for departing passengers, London's Heathrow Airport said, having warned of delays.

Brussels Airport and Berlin Airport were also affected by the attack, they said in separate statements.

RTX, Collins Aerospace's parent, said it had become aware of a "cyber-related disruption" to its software in select airports, without naming them.

"The impact is limited to electronic customer check-in and baggage drop and can be mitigated with manual check-in operations," the company said in an e-mailed statement, adding that it was working to fix the issue as quickly as possible.

The attack has rendered automated systems inoperable, allowing only manual check-in and boarding procedures, Brussels Airport said on its website, adding the incident had occurred on Friday night.

"This has a large impact on the flight schedule and will unfortunately cause delays and cancellations of flights...The service provider is actively working on the issue and trying to resolve the problem as quickly as possible."

Passengers with flights scheduled for Saturday were advised by the affected airports to confirm their travel arrangements with their airlines before heading to the airport.

"Due to a technical issue at a system provider...there are longer waiting times at check-in. We are working on a quick solution," Berlin Airport said in a banner on its website.

Frankfurt Airport, Germany's largest, was not affected, a spokesperson said. An official from the operations control centre at Zurich Airport also said it had not been impacted.