LUCKNOW - A special court in India has sentenced 47 policemen to life in prison for killing a group of Sikh pilgrims in 1991 whom they had claimed were militants, a prosecutor said Tuesday.

The officers were convicted of shooting dead the pilgrims to try and earn promotions in Uttar Pradesh state which at the time was hit by Sikh militant activity, the Press Trust of India (PTI) said.

The officers stopped a bus carrying the pilgrims and their families before later marching 11 of them into a jungle area of the northern state and carrying out the killings, prosecutor SC Jaiswal said.

“The court observed that there was ample evidence to award life sentences to the guilty,” Jaiswal told AFP of the court’s decision on Monday. “The court specifically observed that a crime of such magnitude could not have happened without the knowledge of those higher up and they too should have been charged.”

The court of the Central Bureau of Investigation (CBI), India’s leading investigative agency, found the police guilty of carrying out a “fake encounter”.

The term is commonly used term in India for staged confrontations in which police or military forces execute unarmed suspects and later claim it as self-defence.

At the time of the killings, militants were fighting in the region to try to create a Sikh homeland called Khalistan.

The Supreme Court, acting on a lawyer’s petition, ordered the CBI to investigate the case. The CBI charged 57 police in 1995 but 10 of them died during the eventual trial that took years to conclude in India’s notoriously slow legal system. The remaining 47 were found guilty on Friday.

Meanwhile, three low-caste teenagers were stripped, beaten and forced to march naked in public after they were accused of stealing a motorcycle in western India, video footage showed on Tuesday.

Angry villagers reportedly tied the children, aged between 13 and 15, to a tree, thrashed and stripped them naked in Rajasthan state’s Chittorgarh area after they were accused of stealing an upper-caste man’s motorcycle.

The footage on the NDTV news channel showed a group of men hitting the naked teenagers, from India’s lowest Dalit caste, as they appeared to crouch down to save themselves from the blows.

Police said they had registered cases against both the boys and their attackers after the assault, which occurred on Saturday.

“It isn’t an upper caste versus lower caste case. This is a case of theft and mob fury - both are wrong. We arrested six from the mob today,” Gaj Singh, a senior police officer of Chittorgarh, told AFP by telephone.

Singh said the villagers involved in the assault were also from the same Kanjar tribe as the victims.

Kanjars are a socially stigmatised nomadic community found across northern and central India whose members often face such discrimination that they are forced to live outside villages and towns.

Manan Chaturvedi, the head of Rajasthan’s child rights commission, promised to investigate.

“We are forming a committee that will investigate this matter and then appropriate action will be taken after proper evidence is found,” she said. “Not only the police, but those bystanders watching and taking videos should have been active. Had they stepped in, I don’t think any of this would have happened.”

Kailash Satyarthi, the Indian child rights activist and Nobel peace laureate, called on his Twitter followers to demand “immediate action” over what he called a “barbaric attack”.

Caste discrimination is officially illegal in India. But it still pervades many aspects of daily life, especially in the underdeveloped rural areas where more than half the population lives.