The two trainee officers were reprimanded, The Local reported. They will also be fined 72 kronor ($11) a day for 10 days.
Officials at the Land Warfare Center in Skovde said no trainees got a chance to be scared by the dungeon since staff members discovered it before anyone except its creators had seen it.
The dungeon included an altar with animal bones and smeared with what appeared to be blood and feces.
"This is a totally short-sighted and foolish prank. It is completely stupid and I do not in any circumstance condone that sort of behavior," Col. Mikael Claesson, the center's commander, told the newspaper Aftonbladet.
"They have told me that it was a case of student humor. A boyish prank. They have expressed their deepest regret to me in person and they know that what they did was inappropriate."