"They were both released after questioning. The suspicions remain and the investigation continues," senior prosecutor Lisa dos Santos said in a press release.
Three other people, all students at the school, are in custody in the case. Two are suspected of sexual harassment and aggravated assault, and one is suspected of assault and unlawful coercion.
The prosecutor has previously said the suspected crimes are considered to have been committed as part of an "ongoing system of control and punishment."