A cyberattack targeting a service provider for check-in and boarding systems has disrupted operations at several European airports, causing flight delays and cancellations at airports in Brussels and Berlin, the operators said.

The attack has rendered automated systems inoperable, allowing only manual check-in and boarding procedures, according to Brussels Airport.

"This has a large impact on the flight schedule and will unfortunately cause delays and cancellations of flights," the operator said in a statement published on its website.

"The service provider is actively working on the issue and trying to resolve the problem as quickly as possible."

Passengers with a flight scheduled for Saturday were advised to confirm their travel with airlines before heading to the airport.

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