(AP) - A female high school teacher accused of having sex with six male students has pleaded not guilty.

Nicole DuFault, of Caldwell, was charged with aggravated sexual assault and child endangerment in a 40-count indictment handed up in February. She entered her plea Monday during a court hearing in Newark.

Authorities say the victims were 14 and 15-year-old boys and the assaults occurred many times in 2013 and 2014. Some of the sex acts allegedly occurred on school property and in DuFault's car.

The 35-year-old DuFault was a language arts teacher at Columbia High School for several years before she was arrested last September. She's been suspended without pay and remains free on $500,000 bail.

Her attorney has said the charges "run contrary to her commendable background and unblemished work performance."