(CNN) The Burundi schoolgirls detained for drawing on a photo of President Pierre Nkurunziza in their schoolbooks have been freed, a Human Rights Watch official told CNN on Wednesday.

Human Rights Watch Central Africa director Lewis Mudge said the three girls were freed from Ngozi Central Prison two days after Justice Minister Aimée Laurentine Kanyana told state broadcaster RTNB that their provisional release had been approved.

The schoolgirls were charged March 18 with "insulting the head of state" and faced up to five years in jail if they were convicted.

CNN was not immediately able to reach the Burundi government for comment on the case.

The schoolgirls' detention led to international condemnation of the Burundian government, with critics showing their support for the girls on social media with crudely drawn images of Nkurunziza and the hashtag #FreeOurGirls.