A 25-year-old Pakistani woman has been stoned to death by her family outside the Lahore High Court in a so-called 'honour killing' for marrying the man she loved, police said.

Farzana Iqbal was waiting for the court to open when a group of around dozen men began attacking her with bricks, said senior police officer Umer Cheema.

Her father, two brothers and former fiance were among the attackers, he said.

Ms Iqbal suffered severe head injuries and was pronounced dead in hospital.

All the suspects except her father escaped arrest.

He admitted killing his daughter and explained it was a matter of honour.

Many Pakistani families think a woman marrying her own choice of man brings dishonour on the family.

Ms Iqbal had been engaged to her cousin but married another man, Mr Cheema said.

Her family registered a kidnapping case against her husband, but Ms Iqbal had come to court to argue that she had married of her own free will, he said.

'Huge legal flaw'

Around 1,000 Pakistani women are killed every year by their families in 'honour killings', according to Pakistani rights group, the Aurat Foundation.

However, the true figure is probably many times higher since the Aurat Foundation only compiles figures from newspaper reports.

The government does not compile national statistics.

Campaigners say few cases come to court, and those that do can take years to be heard.

No one tracks how many cases are successfully prosecuted, and even those that do result in a conviction may end with the killers walking free.

Pakistani law allows a victim's family to forgive their killer, but in honour killings, most of the time the women's killers are her family, said Wasim Wagha from the Aurat Foundation.

The law allows them to nominate someone to do the murder, then forgive him.

"This is a huge flaw in the law," he said. "We are really struggling on this issue."

Reuters