Two police officers were among those killed in the overnight clashes during a move to expel around 3,000 sect followers who had illegally occupied public land in the state of Uttar Pradesh for the last two years.
Police and other officials said they came under fire from members of the sect who were armed with automatic weapons and also hurled crude explosive devices during the violence in the northern city of Mathura.
Sectarian violence: Over 2,000 people killed in 5 years, Interior Ministry tells Senate
"They were firing at us from tree-tops. Others were hurling stones or assaulting us with sticks and other weapons. Two of our men were wounded and they died in hospital," said Uttar Pradesh police chief Javeed Ahmad.
"Soon after the attack, we got reinforcements and launched a counter-attack on the camp and successfully cleared the area."
Speaking to reporters in Mathura, Ahmad said some of the Swadhin Bharat Vidhik Satyagrah sect's followers had set fire to huts which were storing gas cylinders and explosives during the clearance operation.
"Twenty-two of their people have died, out of which 11 have died due to burn injuries. One of the dead is a woman," he added.
Police have also recovered several dozen pistols and rifles along with live ammunition rounds.
Communal violence claims 21 lives in India
The operation was launched after authorities won a court order to remove hundreds of tents and makeshift wooden structures from a 270-acre (109-hectare) patch of land the sect had been occupying since late 2014.
Television images and pictures from the scene showed many of the huts where members of the sect had been living on fire, with smoke billowing across the area.
In postings on social media, Swadhin Bharat Vidhik Satyagrah's followers describe themselves as political and social revolutionaries. Their demands include the abolition of elections and cheaper fuel for everyone.
"Their ideology is similar to the Naxalites," said divisional commissioner Pradeep Bhatnagar, who is the top civilian official for the area.
Naxalites are Maoist revolutionaries who have been waging a four-decade long insurgency in parts of eastern and central India.
Hundreds of people were detained over the violence, including 124 who have been formally charged with rioting and murder.
"We have identified four leaders of this illegal group. We are looking for them and will arrest them soon," said Ahmad.
"We are trying to identify the bodies and it is possible some of them may be the wanted leaders."
One of the police officers who was killed was a superintendent, the most senior officer in Mathura, which is around 150 kilometres (90 miles) east of the capital New Delhi.
The Swadhin Bharat Vidhik Satyagrah sect is led by a man called Ram Vraksha Yadav, whom police say was at the park when the violence broke out but has so far eluded arrest.
In several videos posted on YouTube, Yadav can be seen pledging allegiance to Indian independence hero Subhash Chandra Bose and the Azad Hind Fouj (Indian National Army), a rebel movement founded by Bose to combat British colonial rule.
Communal violence claims 21 lives in India
The group describes itself as the legitimate government of India and is headquartered in the park that was cleared by police.
India is home to hundreds of semi-religious sects which are often led by charismatic self-styled "godmen".
In 2014, hundreds of armed supporters from another sect clashed with police in the northern state of Haryana during a raid to arrest their leader who faced murder allegations. At least six people died in the violence.
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