A Pakistani couple accused of killing their 15-year-old daughter by pouring acid on her carried out the attack because she sullied the family's honour by looking at a boy, the couple said in an interview broadcast  by the BBC.

The girl's death underlines the problem of so-called "honour killings" in Pakistan where women are often killed for marrying or having relationships not approved by their families or because they are perceived to have somehow dishonoured their family.

The girl's parents, Mohammad Zafar and his wife Zaheen, recounted the October 29 incident from jail. The father said the girl had turned to look at a boy who drove by on a motorcycle, and he told her it was wrong.

"She said 'I didn't do it on purpose. I won't look again.' By then I had already thrown the acid. It was her destiny to die this way," the girl's mother told the British broadcaster.

Television footage of the couple showed them standing behind bars in separate, but adjoining jail cells.

The father said the family had already come under public censure because of their older daughter's behaviour, but he did not detail what exactly he meant.

Pakistani officials initially said the attack occurred because the girl supposedly had an affair with a boy.

According to the Human Rights Commission of Pakistan, at least 943 women were killed in the name of honour last year. Only 20 of the women were reported to have been given medical care before they died, the report said. The real toll is believed to be higher because many of the crimes go unreported.

"Throughout the year, women were callously killed in the name of honour when they went against family wishes in any way, or even on the basis of suspicion that they did so. Women were sometimes killed in the name of honour over property disputes and inheritance rights," the report said.

- AP