A criminal gang’s effort to make video tutorials on bombing ATMs has really blown up in their faces after two of its members had an explosive accident while filming a trial attack. Europol officials said Thursday that one suspect was killed and an accomplice badly injured at an illegal “training center” in the Netherlands. The 24-year-old accomplice was taken into custody shortly after the failed detonation, which happened in September 2020. His arrest was one of nine made over the course of an international 18-month operation. The agency said that the investigation had linked the gang to at least 15 cash machine bombings in Germany.

The operation kicked off after officers noticed “suspicious orders” of ATM machines from a German company. Eventually, surveillance led investigators across the border into Utrecht, where the two suspects were running the training center, filming videos on the most effective ways to blow up ATMs to give “in person to other criminals.” Europol and its sister agency Eurojust explained in a joint statement that “the cash machines were blown open using homemade explosive devices, posing a serious risk for residents and bystanders.” Bomb attacks, the agencies said, are a “growing concern” for European authorities.