In a submission to India's Supreme Court, leaders of caste councils made a plea for greater understanding of those who kill their children for 'honour' but denied encouraging them.

Their submission came amid widespread anger in India over high levels of violence against women following the gang-rape and murder of a 23-year-old student on a bus as she travelled home from the cinema with a friend.

According to campaigners there are up to 10,000 'honour killings' in India every year. Most of the victims are young women killed by their fathers and brothers over 'forbidden' relationships or for insisting on marrying a man they love.

Many of those killed were in India's northern states where councils have issued stern warnings against men and women from the same sub-caste marrying each other. Caste elders regard the practice as akin to incest even though the individuals are not related.

Caste leaders have now made a submission to the Supreme Court spelling out demands for new marriage laws banning those in the same sub-castes from marrying one another.