The defence ministry computer network which caused Wednesday’s IT problems at Eindhoven airport and numerous government departments connects all 180 defence ministry locations and 70 other organisations nationwide, tech website Tweakers and other Dutch media have reported.

The Netherlands Armed Forces Integrated Network (Nafin) is a closed, 3,300 kilometre glass fibre network managed by the defence ministry and KPN, and has 7,000 computer connections.  

As yet it is unclear what exactly caused the issue that halted air traffic at Eindhoven airport and disrupted communication between the emergency services, but large parts of the Nafin network are currently being renewed, the AD said.

The defence ministry has not confirmed in Nafin is involved, but has said one of its networks is behind the nationwide outage. It has also said that the problem does not seem to be the work of people with “evil intentions”.

Last year, the national audit office Algemene Rekenkamer began an investigation into the Nafin network’s security, which will be published in two months.

“Vital (digital) infrastructure in Europe is under threat,” the agency said at the time. ”In recent years, incidents of sabotage have become more frequent. The Nafin network is essential for the functioning of the armed forces and the entire central government. Given the threat, this network must be well protected against any cyber attacks.”

The ministry has declined to give any more details. However, Jean Debie from military union VBM told the paper that the outage was “disastrous”. “Our essential services must be able to communicate in all situations,” he said. “We need to scale up to the highest level to find out what is going on and what can be done to prevent it happening again.”

Meanwhile, Eindhoven airport said it hoped the first flights could take off around 5 pm. It was affected by the outage because it is also a military base.

Other systems affected by the outage, including local council offices and the Digid government identification system, began starting up again around 1.30 pm.