He is also charged with violating the Act on Flammable and Explosive Goods, a felony, and with preparing to commit the same crime, the Prosecution Authority says in a press release.
According to police, the bomb was built to detonate in someone's hands.
"All handling of the bomb has been associated with danger to life," says prosecutor Jimmy Skogström in the press release, noting that the bomb may have been intended for an employee at the 18-year-old's school.
A review of the man's computer and mobile phone has shown that he has an interest in serious violent crimes.
