The BBC's Owen Bennet-Jones: "Few cases are investigated"

The Progressive Women's Association says the problem is growing, and very few of the cases are picked up by the police.

It wants legislation to deal specifically with the issue of domestic violence.

"According to the association's findings, bride burning every year accounts for the violent death of at least 300 women, perpetrated most often by the victims' husbands or husbands' families," said the association's Shamoon Hashmi.

While divorce is possible in Pakistan, it is claimed that some families decide instead to murder unwanted wives.

In many cases, the police are told the victim was killed by an exploding stove, and there is no prosecution.

Doctors say the injuries to many of the victims they see are not consistent with stove burns, according to the association

'Tip of the iceberg'

The report examines the cases of a dozen women in graphic detail. Most ended with the offenders escaping punishment.

"What we see in this book is the tip of the iceberg," said Anne Kleening, of the United Nations gender programme in Pakistan.

"They opt for burning because the chances of prosecution are less."

It is claimed half of all Pakistani women suffer some form of violence

The Progressive Women's Association's chief co-ordinator, Shahnaz Bukhari, said the report would be sent to Pakistani parliamentarians in the hope of a special law against burnings being passed.

She said: "Every second Pakistani woman is the victim of a direct or indirect form of mental or physical violence, leading to heinous crimes against them including rape, murder, chopping of limbs or being burned alive."

As well as campaigning for protective legislation, she wants to see a support system for women including shelters and legal and financial help.

There is also an urgent need for more specialised burns units in Pakistan's hospitals.

Women's rights group are becoming more vocal

It has been a long struggle for Shahnaz Bukhari and others like her.

Earlier this month, the upper house, the Senate, rejected a resolution condemning the practice of murdering women in the name of family honour.

Human rights groups had been calling for a new law to discourage the custom.

While the government has often dismissed claims that it does not protect the rights of women and ethnic minorities, there are signs of change in the air.