Around a thousand students of an elementary school in the Croatian capital Zagreb boycotted classes on Tuesday after a boy accused of bullying returned to school, state-run HRT television reported.
The unprecedented case of the nine-year-old boy who had to quit his previous school due to accusations of bullying has shaken the country's education system.
The boy was transferred to his current school in early October after the entire class in his previous school walked out due to his bullying, according to his parents' testimonies.
Parents said the boy's behaviour included violent physical attacks, threats, use of offensive language and sexual harassment, while media reported than the majority of his classmates had to seek physicological help.
He was transferred to a new school, but parents there rebelled, claiming that they had not been informed in advance and that he had started to behave aggressively again.
The boy's classmates already boycotted classes for five days earlier this month and he stopped attending classes. But he returned to school with an education assistant on Monday.
The headmaster immediately resigned, citing "pressure" on the school.
Meanwhile, a few hundred parents gathered in front of the school on Tuesday evening.
"Help the boy! Act!" and "Who failed within the system?" read some of the banners placed on the school's fence.
Parents, who claim their children's safety is threatened, repeatedly said they were not protesting against the boy but rather against the system they label inefficient.
"We came to voice our dissatisfaction with the outcome, which is the result of the ineffectiveness of the system, which shifts its failures, inefficiency and all responsibility to the schools," a protester told the crowd Tuesday.
Parents said the boycott would continue on Wednesday.
Meanwhile, Education Minister Radovan Fuchs called for the return of children to school.
"We guarantee the normal development of the teaching process. This is a very sad story," he said.