(CNN) Three schoolgirls in Burundi spent the weekend in jail and are facing five years in prison for drawing on the President's face in their school books, Human Rights Watch told CNN.

The girls, who are all minors, were arrested last week and were on Monday charged with 'insulting the head of state,' according to the human rights group.

They are on remand while they await trial for drawing on President Pierre Nkurunziza's face during one of their classes, Lewis Mudge, the Central Africa Director at Human Rights Watch told CNN.

4/5 This is not the first time children are targeted with political repression in Burundi. In 2016 authorities also arrested schoolchildren for doodling on images of Nkurunziza.https://t.co/uUQKVElFcK pic.twitter.com/D0uGNTC7KV — Lewis Mudge (@LewisMudge) March 20, 2019

A 13-year-old girl was released for being below the age of criminal responsibility while four others arrested alongside the schoolgirls were released.

Mudge said textbooks in Burundi's school system are often passed in between classes and it is, therefore, difficult to know who scribbled on the President's image in the first place.