Airbus SE and Alstom SA are deepening a partnership on cybersecurity to counter threats they say are growing against rail transport systems.

The French plane and train manufacturers signed a cooperation agreement to provide security systems to rail operators, according to a statement Wednesday. The move comes as cross-country networks and urban metros and trams become increasingly reliant on software.

“It’s a really important issue for the rail industry,” Eddy Thesee, vice-president of cybersecurity at Alstom, said in an interview. Networks have grown into major data treatment centers that have the same vulnerabilities as more classic software operations, he said. 

A ransomware attack on German train operator Deutsche Bahn AG in 2017 caused computer turmoil, while a similar incident in San Francisco a year earlier affected the city’s transit system.

Airbus has developed a cybersecurity division for military and commercial aviation that it’s now extending to rail through the agreement.