Thieves broke into a tank at a military barracks near Munster, northern Germany, and stole several assault rifles, a pistol and a flare gun, according to the German Defence Ministry.
The unidentified thieves also took two magazines without ammunition, two radio devices and a pair of binoculars. The theft happened on 13 February, but the ministry only announced it today.
It is the latest blow for the German army which has been rocked by a series of controversies in recent months.
Last week, inspectors found Nazi memorabilia at a garrison in southwest Germany. Several Nazi-era helmets and pictures of soldiers from the Wehrmacht, the army which served Adolf Hitler, were found at a barracks in Donaueschingen.
The discovery came after Defence Minister Ursula von der Leyen summoned an emergency meeting of the country's top military officials to discuss growing concerns that far-right extremism has infiltrated German forces.
Von der Leyen criticised her own army of suffering from an "attitude problem," a "misunderstood esprit de corps" and "weak leadership at different levels" on national television after German army lieutenant Franco Albrecht was arrested on suspicion of plotting a racist attack. She criticised the lieutenant's superiors for not stepping in when they became aware of his "primitive racial ideas."
The 28-year-old lieutenant managed to successfully register for refugee status in Syria in 2015, despite the fact that he couldn't speak Arabic and was not of Syrian origin. Police said he was motivated by a "xenophobic background" to carry out a "serious crime endangering state security."
A spokesperson for Bundeswehr, the association representing German soldiers' interests, told German newspaper Die Welt that the robbery case has been handed over to the Prosecutor's Office in the city of Lueneburg.