FILE PHOTO: KPN logo is seen at its headquarters in Rotterdam, Netherlands, January 30, 2019. REUTERS/Piroschka van de Wouw/File Photo

AMSTERDAM (Reuters) - A nationwide telecommunications outage in the Netherlands knocked police and emergency numbers offline for roughly four hours on Monday before national carrier Royal KPN NV said service was restored.

The cause of the outage remained unclear, but the company said it did not appear to be the result of a security breach.

“We have no reason to think it was (a hack) and we monitor our systems 24/7”, a KPN spokeswoman said.

Anna Posthumus, a spokeswoman at the National Coordinator for Security and Counter-Terrorism, said it is “too early to say” whether there may have been a cyber attack.

The outage was the largest in memory in the Netherlands, a nation of 17 million which prides itself on the technical prowess of its telecommunications infrastructure.

It originated on KPN’s network, but also affected other telecommunications providers using its infrastructure backbone.

Emergency contact numbers went down, prompting the government to advise people to “go to the hospital yourself.”

People with emergencies had been instructed on Twitter to go directly to hospitals, fire departments or local police stations.

The military police, which guards international borders, temporarily increased its presence at vital military locations and airports.