In a report from Yemen, Leila al-Fuhaidi of AFP highlights an unusual practice that can lead to happily married couples being forced to divorce.

The practice – found mainly in rural areas – involves an "exchange" marriage known as sheghar, where two men from different families each marry the other's sister.

It's especially attractive to poor families, since no dowry is required (and in Yemen the size of dowries can often make marriage prohibitive).

Problems with sheghar arise if one of the marriages breaks down. The "exchange" agreement becomes void and the other couple also have to separate – whether or not they want to.

Fuhaidi writes:

One of the reasons leading to the spread of swap marriages in rural areas is the lack of education for women who remain too weak to reject the will of their male-dominated families.

Most women in Yemen do not have the option of disobeying the family because that would amount to challenging the whole clan, which is far more concerned about preserving its honour than it is about the life of a woman on the verge of losing her family.

Ali and Nasser married each other's sisters. After several years, Ali divorced his wife. But when his sister refused to leave Nasser, her family and cousins stormed her house and forced Nasser to divorce her.

The dispute led to armed clashes between the two families which resulted in the death of Nasser's brother-in law.

"The revenge is yet to be settled between the two families," said Saeed al-Waeli, a relative of the victim.

Fuhaidi notes that religious authorities disapprove of shegharmarriages, saying they conflict with the rules of sharia.

Posted by Brian Whitaker, 3 November 2012