BRUSSELS (AP) -- A cyberattack targeting check-in and boarding systems disrupted air traffic and caused delays at several of Europe's major airports on Saturday, officials said, though the initial impact appeared to be limited.

The disruptions to electronic systems initially reported at Brussels, Berlin's Brandenburg and London's Heathrow airports meant that only manual check-in and boarding was possible. Many other European airports said their operations were unaffected.

"There was a cyberattack on Friday night 19 September against the service provider for the check-in and boarding systems affecting several European airports including Brussels Airport," said Brussels Airport in a statement, initially reporting a "large impact" on flight schedules.

Airports said the issue centered around a provider of check-in and boarding systems -- not airlines or the airports themselves.

Collins Aerospace, whose systems help passengers check themselves in, print boarding passes and bag tags and dispatch their luggage from a kiosk, cited a "cyber-related disruption" to its MUSE (Multi-User System Environment) software at "select airports."

As the day wore on, the fallout appeared to be contained.

Brussels Airport spokesperson Ihsane Chioua Lekhli told broadcaster VTM that by mid-morning, nine flights had been canceled, four were redirected to another airport and 15 faced delays of an hour or more. She said it wasn't immediately clear how long the disruptions might last.

Axel Schmidt, head of communications at the Brandenburg airport, said that by late morning, "we don't have any flights canceled due to this specific reason, but that could change." The Berlin airport said operators had cut off connections to affected systems.

Heathrow, Europe's busiest airport, said the disruption has been "minimal" with no flight cancellations directly linked to the problems afflicting Collins. A spokesperson would not provide details as to how many flights have been delayed as a result of the cyberattack.

The airports advised travelers to check their flight status and apologized for any inconvenience.

Collins, an aviation and defense technology company that is a subsidiary of RTX Corp., formerly Raytheon Technologies, said it was "actively working to resolve the issue and restore full functionality to our customers as quickly as possible."

"The impact is limited to electronic customer check-in and baggage drop and can be mitigated with manual check-in operations," it said in a statement.