FILE PHOTO - Aerial view of Schiphol airport near Amsterdam April 9, 2014. REUTERS/Yves Herman

AMSTERDAM (Reuters) - A major computer malfunction crippled traffic at Amsterdam’s Schiphol airport for hours on Wednesday, causing delays or cancellations of more than 100 flights at one of Europe’s largest transportation hubs.

The outage was cause by faulty hardware, the Netherlands’ Air Traffic Control said in a statement issued seven hours after the first problem was reported. An initial reboot of computer systems in the morning had failed to resolve the issue.

“Air traffic is being restored to the normal situation” after capacity had been severely cut back, the statement said.

Passengers faced hours of delays as flights were diverted to alternative European airports including Munich and Rotterdam, a spokesman said. Schiphol ranks among Europe’s most congested airports with 58 million passengers in 2015.

KLM, the Dutch national carrier, canceled flights to Germany, Belgium, France, Britain and the United States, among others. KLM reported widespread flight disruptions and advised passengers to rebook travel or seek a refund.