A young girl playing the role of a mother lifted up her son's shirt to show bruises on his back, which had been inflicted by the boy's teacher.
"Is he a farm animal?" she asked a boy, who was acting as headmaster. "Would you beat a farm animal like that?"
The play was part of a drama series organised by the United Nations Children's Fund (UNICEF) Theatre for Life (TFL) project, which organises workshops where children write and act in plays about harmful Sudanese traditions in front of adult audiences.
The traditions include female genital mutilation, low female enrolment in school, child soldiers and corporal punishment.
Paul Moclaire, TFL project manager said corporal punishment was the most popular topic in Kadugli in the Nuba Mountains, Nyala in Darfur, Gedaref and Wau in the south.
"In all the workshops, children have signalled teacher violence as an issue they wanted to work on. They identify it as a source of misery in their lives," he said.
Yet Sudan adopted the UN Convention of the Rights of the Child in 1983 - a set of child rights-based laws that, among other things, are meant to protect children from physical abuse.
Yousif Ahmed Alfadil, a teacher at the Ahmed Bashir Al Abadi school in Omdurman, said: "Punishment is important because they [the students] don't care about their work and they are lazy so we must punish."
However, he insisted, physical beatings were "not done in a hard way". Usually the children were beaten by hand or with a stick.
Teachers too used other forms of discipline such as staying after school to clean the classroom, Alfadil said, but beatings were the more severe form of punishment.
Asthma Hamid, the director of Girl's Education at the education ministry confirmed that beatings are a common form of punishment in Sudanese schools.
"In schools around Khartoum, teachers beat students with sticks if they do not understand," Hamid said.
The ministry has conducted several seminars in the capital, Khartoum and surrounding areas to educate teachers about child rights, but changes in attitude were slow in coming.
"We try to teach them that this is a negative way to discipline, but they don't understand because this is the way they [the teachers] were taught," she said. "They not only view it as harmless but also as necessary."
Sudanese children do not necessarily condemn corporal punishment by teachers either, according to responses during a discussion at the TFL workshop in Wau.
Jeskar Jamesto felt that corporal punishment was "good because it helps us to learn."
After the play ended, the children discussed methods to stop teacher-based violence. Their responses indicated that they associate the problem with their own behaviour.
"We can stop teacher violence by showing more respect for the teacher," observed Christina Sepriano.
Another primary student indicated that the key to ending the violence was "behaving well".
According to Moclaire, these views were reflected in all the TFL workshops. Even trainees who were expected to promote child rights in subsequent workshops were often in favour of corporal punishment in schools.
One trainee in Wau, who was appalled by the children's complaints about corporal punishment, said: "These children go to a very good school. They are only beaten when they do something wrong!"
According to Moclaire, six of the 50 adults who were trained as facilitators for the workshops were themselves teachers.
"Adult trainees were visibly taken aback at the power and clarity with which children expressed their own ideas once they were given the freedom to do so," Moclaire added.
"In Sudan we are trying to overcome deeply ingrained, negative attitudes towards women and children. There is also the problem that many of the issues highlighted are linked with chronic poverty. No amount of performances or perceptive debates will alter that fact," he said.
Moclaire maintained, however, that despite slow progress, establishing a child rights-based society in Sudan was an important investment in the country's future.
"[It] helps [to] encourage tolerance and dialogue," he observed. "These are exactly the skills that a new generation of Sudanese need as the country finally tries to limp away from war."