New Delhi - An unofficial, all-male village council in India's Uttar Pradesh state has ordered the rape of two young sisters after their brother eloped with a woman of a higher caste, a report published on the Hindustan Times said.

The 'sentence' was handed down after the brother of 23-year-old Meenakshi Kumari and her 15-year-old sister ran off with a married girl belonging to the dominant Jat community.

The tribunal - locally known as a panchayat - also ordered for the sisters to be paraded naked with their faces blackened.

After receiving threats, Kumari and her family - who belong to the Dalit caste, also referred to as 'untouchables' - fled their village in UP's Bhagpat district for New Delhi, some 50 kilometres away.

The appalling punishment was brought to light after rights group Amnesty International launched a petition calling for local authorities to intervene immediately and save the girls from being raped.

Amnesty says in the petition: "Nothing could justify this abhorrent punishment. It's not fair. It's not right. And it's against the law."

According to the Hindustan Times report, Kumari filed a petition in India's Supreme Court, seeking protection for herself and her family.

She alleged that local police filed a false narcotics case against her brother, under pressure from the Jat girl's family. Even though he was granted bail by a local court, the family was too afraid to go back to the village to arrange surety documents to get him released.

A Supreme Court bench issued a notice to authorities, asking for a probe into the incident. Kumari said in the petition that her brother and the girl were in love for the past three years. However, the girl was married off to boy from the Jat community against her wishes.

A month after her marriage, the girl escaped her husband's home and eloped with Kumari's brother. The couple surrendered after alleged torture by the girl's family and UP police.

The girl, who claimed she was pregnant with her lover's child, was sent back to her parents while the boy was detained under a false drug case.

After Kumari's family moved to Delhi, fearing for their lives, their house was allegedly ransacked and taken over by members of the Jat community.

Hindu scriptures separate people into Brahmin priests, warriors, farmers and labourers, while the rest are beyond definition - called Dalits.

These low-caste Hindus were once considered "untouchables", performing the most menial and degrading jobs.

The ancient caste system has persisted in India - mostly in villages - despite the country's economic success and exposure to Western culture which has re-moulded social paradigms in the nation.

Rachel Alcock, Amnesty UK's urgent action coordinator, said: 'Rape is a revolting crime, not a punishment. It's no wonder this disgusting 'sentence' has provoked global outrage.

'These Khap courts routinely order vile sexually violent punishments against women. India's supreme court has rightly declared such orders illegal. 'The government of Uttar Pradesh has an urgent duty to keep this family safe.’

'There must also be a proper, independent investigation into these barbaric and illegal orders which apparently continue to be issued by the khap panchayat courts.'