Three Massachusetts teens charged in the bullying of 15-year-old Phoebe Prince, who committed suicide in January, have pleaded "not guilty."

The teens entered the pleas Tuesday through their lawyers, and did not appear in court.

Kayla Narey is charged with civil rights violations and harassment. Sean Mulveyhill and Austin Renaud are also charged with statutory rape. Their pretrial hearing is set for September 15.

Six more teens face charges in what prosecutors call the "unrelenting" bullying of Prince.

Authorities said the teens harassed Prince after she had a brief relationship with a popular boy at her school, South Hadley High. They say that she killed herself after months of repeated insults and threats.