A safe full of cash went missing from the Ninja Museum in Japan in a stunt that could only be pulled by…trained ninjas.

Thieves came in during late hours of the night and nobody was able to spot them or even get a hint of their presence in the museum. Moments later, when they left, a safe of 150 kilogramme was missing.

The Iga-ryu Ninja Museum in central Japan is a popular tourist attraction and is dedicated to the Ninja legendary group that is known for its stealth mode and secrecy.

Early investigation reports assumed the museum was robbed in a similar fashion as the lga-ryu ninja group’s techniques. However, later investgations revealed that the theives were not as skillful as the well-known ninjas, as the thieves had forced their way into the museum office with a crowbar.

The safe that weighed around 150 kgs (330 pounds) had nearly $9,500 that the museum had collected from the visitros in form of admission fee over 1,100 weekends.

The museum honours two of the famous ninja clans based out of Iga, which is 350 kilometres (220 miles) southwest of Tokyo. It allows visitors to learn about the ninja skills, throw star-shaped weapons and live the ninja-experience by offering interactive experiences.