Agnes Poroi is the sort of teacher who oozes warmth and practical common sense. She needs to, because her subject is the most sensitive and the most controversial she could ever have to deal with in this part of East Africa.

Cathy Jenkins reports on female circumcision

She is explaining to a class of 37 girls the dangers of female circumcision, commonly known in health circles as female genital mutilation.

"What does the clitoris do?" she asks the girls, and a dozen hands shoot up. "Yes," says Agnes "it sends messages to the brain. Look at me, I've been circumcised, I don't have a key to start my engine".

Teacher who oozes warmth

Agnes goes on to list some of the side effects: trauma, bleeding, difficult childbirth. Then she tells the girls, in no-nonsense terms, what she remembers of her circumcision day.

"Painful, yes, it was painful what happened to me that early morning. The old mama came, she was very fat. In the first place I was taken outside. No one talked to me. Everyone was rough to me because there was something that was going to happen to me, and they wanted me to be brave."

The old mama whom Agnes was refering to was the old woman who carried out the circumcision. It is a tradition which is still widely practised by many of Kenya's tribes.

Correspondent Cathy Jenkins

The most basic type of circumcision is the "sunna", where the covering of the clitoris is removed. Among Agnes's tribe, the Masai, circumcision is more severe. It involves the cutting away of the whole clitoris, together with the labia majora and the labia minora.

Traditionally, a Masai girl is circumcised before she is married, and that can be from a very young age. During the ceremony, the girl is expected to remain silent. To cry would be a sign of weakness.

Agnes works for an organisation called Maendeleo ya Wanawake, which means the Development of Women - it is trying to stop the practice in Kenya. But so sensitive is the issue that campaigners cannot approach it head on.

Instead they are using education and economic factors as a lever. Among the Masai community, parents are increasingly eager for their daughters to finish school because this increases their chances of earning money for the whole family.

But the problem is that once a girl is circumcised, she drops out of school to get married. Her earning power drops to nil.

Economic factors are a lever

"I had to go around the area for one year without even mentioning female circumcision" says Agnes. "I just had to go round saying to parents 'I'm here and I want to know why your girls are dropping out of school; what will you think if they're not the teachers of tomorrow, not the doctors of tomorrow?' Slowly it came from the parents themselves. 'What about this circumcision. It makes them drop out of school.' "

The parents of the girls in Agnes's class have been convinced. Instead of having their daughters circumcised, they have sent them to Maendeleo ya Wanawake. Over the course of a week with the organisation, the girls are taught what their community expects of them as adults.

Then at the end there is a ceremony of singing and dancing. It is a rite of passage for the girls and marks their passage from childhood to adulthood. But they have become women without being cut.

Dorcas Samante is very happy about it. She is twenty, and first heard about the dangers of circumcision when she was at school. But she only avoided circumcision because her uncle, who brought her up, is an urban, educated man who was already convinced.

Dorcas needed his support because among Masai it is the men who make all the decisions. But Dorcas knows that many of her former schoolfriends do not understand her.

Female circumcision ceremony

"They see me as odd" she says. "They keep away from me. But I'm proud. Perhaps I'm an unusal woman here, but there is an outside world and I know that it will agree with me."

Watching the ceremony is Mary Karanja, the mother of another of the girls, Esther. Mary is beaming with delight. She says that she was circumcised in 1956, but none of her six daughters has been cut.

"I realised when my first child was born that I had difficulty. I am very happy about this ceremony" she says.