A FEUD over church discipline allegedly led to attacks in which the beards and hair of men and hair of women were cut in America.
The Amish believe the Bible instructs women to let their hair grow long and men to stop shaving once they marry.
The defendants entered the pleas before US District Court Judge Dan Polster in response to an updated indictment.
The latest indictment added new allegations that the suspects tried to hide or destroy evidence, including a disposable camera, shears and a bag of hair from the victims.
Lawyer Linda Schrock, daughter of alleged ringleader Samuel Mullet Sr, said the related extended families are helping each other during the busy planting season with seven defendants still held on bond.
The updated indictment also charges Mullet with lying to federal agents.
The new defendants, Lovina Miller, Kathryn Miller, Emma Miller and Elizabeth Miller, are members of the Amish community in Bergholz in eastern Ohio and are married to some of Mullet's nephews.
The 10-count indictment includes charges of conspiracy, assault and evidence tampering in what prosecutors said were hate crimes motivated by religious differences.