July 8 (UPI) -- Police in the Netherlands arrested six men suspected of preparing to commit kidnappings and hold people hostage after discovering an "underworld" prison equipped with a torture chamber made from converted shipping containers in a warehouse.
In a statement on Tuesday, the National Prosecutor's Office said the seven shipping containers were discovered during a raid last month in a Wouwse Plantage warehouse near the border with Belgium.
The shipping containers were lined with sound-proofing material and heat-insulating foil with handcuffs dangling from the ceiling and attached to the floor. Each was equipped with a camera mounted in one of its corners encompassing a clear view of the entire cell.
The container the suspects called "the treatment room" contained a dental chair with straps to lash one's arms to its armrests and handcuffs at its footrest. Bags were also found in the so-called torture chamber, the statement said, containing "pruning shears, loppers, branch saws, scalpels, pliers, extra handcuffs, finger cuffs, tape, balaclavas and black cotton bags that can be pulled over the head."
In one container, agents also discovered several sets of law enforcement clothing, bulletproof vests and flashlights.
Three stolen vans, two BMWs, seven small guns and a Chinese version of the Russian Kalashnikov AK-47 assault rifle were found in the warehouse, which also contained a sitting and sleeping area believed to be made for guards, police said.
Police arrested the six men on June 22 following an investigation into a 40-year-old man from the Hague suspected of being involved in drug trafficking.
According to the prosecutor's office, amid their investigation police intercepted encrypted phone messages, some of which contained photos of the containers and the dental chair.
"If I have him on the chair more will come," one of the messages said, according to the National Prosecutor's Office, "but the dog is missing."
Police placed the warehouse under observation from mid-April and observed several men working on the containers nearly daily, stating they believed the planned kidnappings were being prepared with "great precision" as there were several so-called teams involved as well as weapons, police clothes, vans, stop signs and bulletproof vests at the ready.
The intended kidnapping targets were deduced, warned and went into hiding, police said, resulting in neither the prison nor the "treatment room" being used.
Police raided 13 locations in total on June 22 when they arrested the half dozen suspects, confiscating 25 weapons and 24 kilograms of MDMA.
A court in Amsterdam has ordered the detention of the suspects for 90 days.