Eight slaughtered over forbidden marriage.

Sign of a mturing nation ?

Eight members of an impoverished family from one of India's most lawless regions were shot and beheaded in a gruesome honour killing after one of their relatives dared to secretly marry a girl from a rival clan in a forbidden "love match".

The killings took place after Ratan Mandal, 21, eloped with Kanchan Kumari, 18, last month, according to police.

The bodies were discovered floating in down the Ganga river in the northern state of Bihar, one of India's poorest territories. Police said they have charged 15 people, most from the Miss Kumari's family, with murder.

"The girl's family invited the boy's family for a meeting on the pretext of settling the dispute [over the marriage], but killed all eight and beheaded them," said Raghunath Prasad Singh, a senior police officer from the district of Bhagalpur.

It is thought that both their families were connected to the underworld and had links with rival gangs. "My son would never have married the girl had he known it would lead to so much of bloodbath," Mandal's mother told reporters.

Violence triggered by forbidden romances and "love marriages" – as opposed to organised unions – is relatively common in Bihar, which also has one of the highest rates of under-age marriage in India.

In November in the same state a teenager who dared to write a love letter to a sweetheart from a higher caste was beaten and paraded through the streets before being thrown under a train and killed.

Fifteen-year-old Manish Kumar, a member of India's Dalit, or "untouchable" community, a group condemned to carry out the country's very worst jobs, was seized by a gang of men as he made his way to his village school. He was beaten and his hair shaved before he was thrown onto the tracks as his mother begged for mercy, witnesses said.

Activists say that such murders underscore how India remains divided by long-standing customs, divisions in wealth and the caste system, an ancient and rigid social structure that dictates that a person's birth governs their profession and status.

Dr Prakash Louis, a sociologist based in Bihar, said: "The intense cruelty of these attacks has captured interest, but similar incidents are occurring daily."