DARIEN, Ill. — A high school student in Darien, Ill., who allegedly threatened to “shoot up” the school has been charged with several crimes after police found firearms, explosives and a Nazi uniform in his residence, according to DuPage County prosecutors said Wednesday.

Prosecutors said the 16-year-old had promised a “Southocaust” and on Monday had made a specific threat against a fellow student on social media. That brought police to his house, where they say they found a flare gun that had been converted to a working gun, as well as a shotgun, a sawed-off rifle, more than 150 rounds of ammunition, knives, ski masks and brass knuckles. His bedroom also contained Nazi posters and flags, a World War II German soldier’s uniform, a Soviet flag and paper targets.

Police said they also found an incendiary device in the boy’s closet that contained black powder, razor blades and ball bearings, and the boy had PVC pipe and other materials commonly used in building pipe bombs.

The teen has been charged with eight felonies and was ordered to be held in a juvenile facility.

How the teenager acquired the cache of weapons is still under investigation.

Despite the discovery of the Nazi uniform, police said there’s no indication of a racial motive or an indication of any accomplice.

The teen’s attorney said the boy’s mother was unaware of her son’s threats and of the materials found in his room.