LONDON:A jury found the Pakistani parents of a teenage girl guilty of murder Friday, a conviction that came after the girl's sister turned against her parents, telling a jury how her mother and father suffocated 17-year-old Shafilea with a plastic bag in a so-called honor killing.  

Iftikhar and Farzana Ahmed face life in prison for killing their daughter in 2003.

The Chester Crown Court found that Iftikhar and Farzana Ahmed killed her daughter in 2003 and dumped her body.

Shafilea's sister Alesha told the jury that her parents pushed Shafilea and then she heard her mother say, ''just finish it here.''

British authorities investigated hundreds of cases of forced marriages last year.

Some of the cases have ended up in so-called honor killings where relatives believe girls have brought shame on their families, sometimes for refusing marriage, other times for becoming too westernized.

Shafilea was only 10 when she began to rebel against her parents' strict rules, according to prosecutor Andrew Edis.

Schoolmates described how she would wear western clothes and change before her parents picked her up.

Those same schoolmates also reported that Shafilea often went to school crying, describing how her mother would slap her and throw things at her.

But it was the last year of her life that was to be the most traumatic, the court heard.    Shafilea began seeing boys, which prompted her parents to keep her at home more.

Despite multiple reports to social services, Shafilea's file was closed in 2002.

Between November 2002 and January 2003, Shafilea told friends and teachers there had been an increase of assaults.

In February 2003, she ran away with her boyfriend Mushtaq Bagas and told council officers she needed emergency accommodation as her parents were trying to force her into an arranged marriage with her cousin.

In the same month, her parents took her to Pakistan where she drank bleach in protest against the arranged marriage.    When she returned to Britain in May 2003, she was admitted to a hospital because of damage done to her throat.    She was eventually released, but rows over her clothing continued.

Eventually, her parents beat her, stuffed a thin white plastic bag into her mouth and held their hands over her mouth and nose until she ''was gone,'' her sister testified.    The highest incidence of reported forced marriages is in Muslim communities.

Britain is home to more than 1.8 million Muslims.