Clifton police said they arrested two men dressed liked ninjas and armed with Asian martial arts weapons who said they were sending a warning to drug users.
Calling themselves "Shinobi warriors," the men wore black SWAT-type vests and carried knives, throwing stars, swords, nunchucks and a bow and arrows.
After being arrested early Wednesday in a car on Route 46, the men said they were delivering warning letters to drug dealers and drug users urging them to stop their "impure" activities.
The letters said those who persisted would be stopped with "justified yet, merciful force."
Tadeusz Tertkiewicz, 20, and 19-year-old Jesse Trojaniak are charged with weapons possession. Tertkiewicz is also charged with harassment for a letter left for an ex-girlfriend.
Trojaniak's father tells The Associated Press his son is "not a maniac" and was only trying to help a friend.