It is still not exactly clear what led to Monday’s communications breakdown which paralysed train travel for several hours, broadcaster NOS said on Tuesday morning.

What is clear, however, is that there was a problem in the communications network used by drivers and traffic managers, which is not due to be replaced for several years, NOS said.

The problems started around 2.40pm and led to passengers being stranded nationwide. It took several hours before services resumed.

The communications system, known as the GSM-R network, is based on GSM technology developed in the 1990s for railway systems throughout Europe and is, said ProRail spokesman Coen van Kranenburg ‘very stable’.

Work is currently underway on developing a new network based on 5G technology. The current system is based on 2G and that is not able to carry camera images, which European railway networks want to bring in.

ProRail expects to be able to say more about the cause of the breakdown later on Tuesday but said until now there are no indications that the system was hacked or attacked by ransomware.