Standing at the front of her classroom, Mulu Melka reads out of her English book in a shy voice like any other 13-year-old schoolgirl; betraying nothing of the fact that twice within two years, she has been abducted and forced into marriage.

A target of the traditional practice, known locally as "marriage by abduction", Mulu managed to escape on both occasions. "The first time I was 11," she recounts. "I was going to the mill, when a group of men grabbed me from behind. They took me by surprise. I fell on the ground, and when I woke up again I was in the house of my abductor. I stayed there three days."

In the meantime, her parents held a meeting with the abductor's parents, mediated by village elders. In exchange for a cow and two sheep, her parents agreed to her marriage with the abductor. But, Mulu ran away one night. "I escaped from the abductor's house while he and his friends were drinking and dancing. I went to the toilet and then I escaped through a fence and ran away."

She then hid for nearly a year in the house of one of her uncles. "After nine months, I could not stand hiding anymore, so I decided to go back to school," Mulu says nervously, looking at her hands.

Later, her parents received a letter from another suitor asking to marry Mulu, but she refused. The 39-year-old man turned up at the house and kidnapped her with her parents' consent. "I managed to get my parents to agree for us to be tested for HIV. I had heard about it at school and on the radio. I was negative but my abductor was positive."

With the test results in her hand, Mulu managed to convince her parents to cancel the wedding.

Unlike Mulu, however, several young girls at Alem Gena school, 30 km south-west of the Ethiopian capital of Addis Ababa, have been forcibly abducted on their way to school and married under duress in exchange of a few sheep or sacks of grain.

"Abduction is a regular phenomenon around here," explains Hundessa Negesso, the headmaster of the 1,500-pupil primary school. "Over the last eight months, seven girls have been abducted. Last year we had three, and none of them came back to school.”

Abduction is a legitimate way of procuring a bride in southern Ethiopia. The practice has been going on so long that no-one can remember how it all began. The usual procedure is to kidnap a girl, hide her, and then eventually rape her. Then, having lost her virginity or becoming pregnant, the man can claim her as his bride.

At this stage, the prospective husband will call the village elders to negotiate the bride's price and to act as middlemen between his family and that of his bride.

According to Hundessa, poverty is a key reason for abduction. "If they marry the girl legally they have to pay a lot of money to her parents. But when it is abduction, they take her by force, and then the elders intervene to mediate. They then pay a very little amount of money or cattle to marry the girl," the headmaster added.

A wedding can cost up to 15,000 birr (US $1,800) in the countryside - a lot of money in a country where nearly 50 percent of the population lives on less than a dollar a day.

According to surveys conducted in 2003 by the National Committee on Traditional Practices in Ethiopia (NCTPE), the prevalence of marriage by abduction is 80 percent in Oromiya Region, where Mulu lives; and as high as 92 percent in Southern Nations Nationalities and Peoples Region (SNNPR); with a national average of 69 percent.

Not always lucky

In many ways, Mulu was luckier than most. Another school friend of hers, Aberash, was 12 when she was forced to marry a 30-year-old man who beat and raped her, causing lasting injuries. Aberash managed to escape and went to her parents' home. But with the consent of the village elders, she was forced to return to her husband.

Eventually, with the help of a teacher, she went back to school and is now trying to get a divorce.

Poverty also means many parents accept their daughter's abduction. "Parents don't have money for their children to go to school so they prefer for them to be abducted and married and be settled," Elleni Mamo, from the United Nations children's agency, UNICEF, explains.

"From the point of view of the community, these early marriages are not really a problem for the parents. Traditionally they represent a way to be able to give financial security to their daughter," explains Kefyalew Ayano, who also works for UNICEF.

The girls who are forced to marry face a number of problems, and often suffer health problems as a result of having sexual relations from an early age. "Most of these girls would just like to go to school like their brothers, but once married they generally have to stay at home, cook and take care of the house. Then they become pregnant and risk a lot of complications," Mamo explains.

"These girls are being violated physically and emotionally. We must work together to educate the boys, girls - and communities as a whole - that this is not an acceptable practice. We must work together to stop these acts of violence," Björn Ljungqvist, the UNICEF representative to Ethiopia, told Irin.

Since 2004, the Ethiopian penal code forbids girls to get married before the age of 18, and punishes marriage by abduction with up to 20 years imprisonment. This is being seen as a real step forward according to a number of humanitarian agencies, but one which needs to be promoted and implemented.

UNICEF and other charities are encouraging families to go to the police rather than to village elders to sort out abduction cases. The message is being spread through schools, communities and radio programmes.

But despite this law, Mulu remains worried she may be abducted again. "I don't want someone to take me by force. I want to go to school and study, and then I will see," Mulu says, hoping one day to become a teacher herself.