THE NETHERLANDS has begun its largest ever security operation, the authorities told reporters today, as The Hague is turned into a fortress for next week’s Nato summit.

Up to 27,000 police officers — about half of the country’s entire force — will be on duty June 24 and 25 along with more than 10,000 defence personnel as the military bloc’s leaders, including US President Donald Trump, descend upon the city.

Car parks have been blocked off by security fencing, workers in nearby offices have been told to stay at home and public transport lines near the World Forum venue, where the meeting is due to take place, have been diverted.

Frigates will patrol the North Sea, F-35 fighter jets and Apache helicopters will take to the skies and air defence systems will be on alert. Bomb squads will comb the venue for explosives.

Police and riot police also will be on hand for several protests that have already been announced, including an effort by demonstrators to shut down a major road into the city.