The Polish Army is promising an investigation following the release of a video showing Polish troops blowing up an Afghan home. An officer serving at the time told the Polish daily that released the report that “it was done for fun.”

Blowing up civilian homes is quite obviously a violation of the Geneva Convention and a potential war crime. The general in charge of the unit insisted that he was never consulted about the destruction, and that they had only “blown up a cave full of explosives.” The video clearly shows a home, however, not a cave.

The Polish Army is said to be investigating the attack, and has come under criticism both from humanitarian groups complaining about the legality of the attack and a retired Army commander who noted that the shells used are quite expensive, costing several hundred dollars each.

Reports suggest that Polish soldiers may have done this fairly regularly, and that blowing up huts in rural Afghanistan was a popular passtime for this unit. Poland has around 2,600 troops in Afghanistan at the moment, its largest foreign deployment.