NAIROBI (Thomson Reuters Foundation) - The schoolboy watched as a man tried to remove the nappy of a little girl he was dragging along a Nairobi riverbank, suspecting that he was going to rape her.
Having been trained to defend girls against sexual assault, the boy called other young men to help him confront the man and rescue the child.
"It would have been fatal," said Collins Omondi, who taught the boy as part of a program to stamp out violence against women and girls in Nairobi slums. "If this man would have assaulted this kid, he would have thrown her inside the river."
Omondi teaches a program called 'Your Moment of Truth', run by the charity Ujamaa Africa which encourages adolescent boys to stand up against violence toward women.
The training is "highly effective" in improving attitudes toward women and increasing the likelihood of successful intervention, researchers from Stanford University, University of Nairobi and United States International University-Africa said.
The training increased boys' successful interventions when witnessing physical or sexual assault by 185 percent, from 26 to 74 percent, according to their study to be published later this year in the Journal of Interpersonal Violence.
Interventions in verbal harassment also increased, and rape by boyfriends and friends of girls in schools where 'Your Moment of Truth' was taught dropped by 20 percent, from 61 to 49 percent, the researchers said.
"Our main focus on the curriculum is positive masculinity for the boys, positive empowerment, and actually making them gentlemen on issues to do with the prevention of rape and standing up for the rights of women," said Omondi, dressed in a black T-shirt with NO! emblazoned on the front.
"If they say the boys are actually the problem, we the boys can actually be part of the solution," he added.
Every secondary school child in Nairobi – some 130,000 students – will undergo the six-week program by the end of 2017 with funding from the British government, which is focusing aid on finding out what works to prevent violence against women.
One in four women and girls in Nairobi's most dangerous slums has been sexually assaulted, Ujamaa said.
Its 'No Means No Worldwide' program started teaching self-defense to Nairobi schoolgirls in 2010.
Ujamaa expanded the program to include boys that same year, as the girls said that the main perpetrators of rape were their boyfriends.
Many of the schoolboys start out with very negative attitudes toward women, the trainers found, believing that it is legitimate to rape girls who they take on expensive dates or who are out after dark.
Before the class, more than 80 percent of boys said that girls wearing miniskirts were inviting boys to have sex with them. Afterwards, it dropped to 30 percent, Ujamaa's data showed.
"It's because of the way they have been brought up," Omondi said.
Violence against women is common in Kenya. Around a dozen women were stripped naked and assaulted last year because they were wearing miniskirts or other clothing perceived to be immodest.
Almost half of Kenyan women who have ever been married have been physically abused by their husbands, according to government data from 2008/9.
Some 53 percent of women believe men have the right to beat their wives for reasons such as arguing with them, neglecting the children or going out without informing them, the same survey showed.
"Their father has been this violent man, has been beating their mum," said Omondi. "He knows this is the best thing."
The program uses social learning theory, whereby people copy the behavior of those around them, to try and get boys to stand up for women and change social norms.
This can involve simple actions, like walking away from a classmate who is talking badly about a girl.
Courage is one of the main lessons.
"Many boys say they cannot intervene in a situation where a girl is being harassed because they feel they are not confident enough," said Omondi.
"But you can stand up and say: 'No. This man is doing something wrong.' Out of that, many other people will join hands with you."
At the end of the class, boys in Nairobi's Makongeni Secondary School do a shout out to build their confidence, punching the air and chanting: "I've got my spirit ... I've got my mind."
Across the dusty compound, girls have their own shout: "I'm dangerous ... Don't touch my body ... Respect my body."
The number of girls dropping out of school due to pregnancy has fallen since Ujamaa started teaching in the school, said Jacklyne Anusu, one of the teachers.
"The girls have become strong," she said. "The boys are trying to accept it also. They realize that these our sisters. We need to help them grow."
Reporting by Katy Migiro; Editing by Alex Whiting