April 3 (UPI) — A computer outage Tuesday caused substantial delays for flights across Europe, officials said.

The Eurocontrol center in Belgium said the failure occurred with its “Enhanced Tactical Flow Management System,” which helps coordinates flight plans.

Officials said there were “no safety implications,” and air traffic controllers were not directly affected.

Nearly 30,000 flights were expected in Eurocontrol’s network Tuesday.

“Approximately half of those could have some delay as a result of the system outage,” it said in a statement.

The aviation body said it addressed the problem and put a contingency plan into place.

Normal flight operations were expected to resume Tuesday night, officials said.