Image caption This child has been temporarily transformed from Mehrnoush the girl to Mehran the boy

For economic and social reasons, many Afghan parents want to have a son. This preference has led to some of them practising the long-standing tradition of Bacha Posh - disguising girls as boys.

When Azita Rafhat, a former member of the Afghan parliament, gets her daughters ready for school, she dresses one of the girls differently.

Three of her daughters are clothed in white garments and their heads covered with white scarves, but a fourth girl, Mehrnoush, is dressed in a suit and tie. When they get outside, Mehrnoush is no longer a girl but a boy named Mehran.

Azita Rafhat didn't have a son, and to fill the gap and avoid people's taunts for not having a son, she opted for this radical decision. It was very simple, thanks to a haircut and some boyish clothes.

There is even a name for this tradition in Afghanistan - Bacha Posh, or disguising girls as boys.

"When you have a good position in Afghanistan and are well off, people look at you differently. They say your life becomes complete only if you have a son," she says.

There has always been a preference for having sons in Afghanistan, for various economic and social reasons.

Ms Rahfhat's husband, Ezatullah Rafhat, thinks having a son is a symbol of prestige and honour.

"Whoever came [to our house] would say: 'Oh, we're sorry for you not having a son.' So we thought it would be a good idea to disguise our daughter, as she wanted this too."

Azita Rafhat is not the only mother who has decided to do this.

Not girlish

Many girls disguised as boys can be found in Afghan markets. Some families disguise their daughters as boys so that they can easily work on the streets to feed their families.

If my parents force me to get married, I will compensate for the sorrows of Afghan women and beat my husband so badly Elaha, Girl who lived as a boy

Some of these girls who introduce themselves as boys sell things like water and chewing gum. They appear to be aged anywhere between about five and 12. None of them would talk to me about their lives as boys.

Girls brought up as boys do not stay like this all their lives. When they turn 17 or 18 they live life as a girl once again - but the change is not so simple.

Elaha lives in Mazar-e Sharif in northern Afghanistan. She lived as a boy for 20 years because her family didn't have a son and reverted only two years ago when she had to go to university.

However, she does not feel fully female: she says her habits are not girlish and she does not want to get married.

"When I was a kid my parents disguised me as a boy because I didn't have a brother. Until very recently, as a boy, I would go out, play with other boys and have more freedom."

She has returned reluctantly to her gender and says she has done it only because of the social traditions.

"If my parents force me to get married, I will compensate for the sorrows of Afghan women and beat my husband so badly that he will take me to court every day."

Common story

Image caption Many girls dress as boys so they can go out to work in the streets

Atiqullah Ansari, head of the famous blue mosque in Mazar-e Sharif, says the tradition is about appealing to the divine.

He says those families who do not have a son disguise their daughters as boys for good luck so that God gives them a son.

Mothers who do not have sons come to the shrine of Hazrat-e Ali and ask him to grant them sons, he adds.

Atiqullah Ansari says that according to Islam the girls who live as boys must cover their heads when they come of age.

In Afghanistan, stories like this have become more common. Almost everyone has relatives or neighbours who have tried this.

You cannot change a girl to a boy for a short period of time - it's against humanity Qazi Sayed Mohammad Sami, Balkh Human Rights Commission

Fariba Majid, the head of the Women's Rights Department in the northern province of Balkh, used to go by the boy's name Wahid.

"I was the third daughter in my family and when I was born my parents decided to disguise me as a boy," she says.

"I would work with my father at his shop and even go to Kabul to bring goods from there."

She thinks that experience helped her gain confidence and helped her get where she is today.

It is not surprising that even Azita Rafhat, mother of Mehran, once used to live as a boy.

"Let me tell you a secret," she says. "When I was a kid, I used to live as a boy and work with my father.

"I experienced both the world of men and of women and it helped me to be more ambitious in my career."

'Breach of rights'

The tradition has existed in Afghanistan for centuries. According to Daud Rawish, a sociologist in Kabul, it may have started when Afghans had to fight their invaders and for this women needed to be disguised as men.

But Qazi Sayed Mohammad Sami, head of the Balkh Human Rights Commission, calls it a breach of human rights.

"We cannot change someone's gender for a while. You cannot change a girl to a boy for a short period of time. It's against humanity," he says.

The tradition has had a damaging effect on some girls who feel they have missed out on essential childhood memories as well as losing their identity.

For others it has been good experiencing freedoms they would never have had if they had lived as girls.

But for many the key question is: will there be a day when Afghan girls get as much freedom and respect as boys?