Police fired on protesters from the nomadic Gujjar tribe who had blocked a key highway near Delhi on Tuesday.
At least two of those killed are believed to be policemen.
The Gujjars are demanding that they be included in an affirmative action quota which would give them access to government jobs and other benefits.
Villagers in Peepalikheda, where some of the clashes took place, are still refusing to release the bodies of six people said to have died in the firing, and are demanding a meeting with government officials.
Soldiers have been deployed to maintain order in Dausa district and the town of Bundi, where some of the worst violence has taken place. The police are stopping vehicles on the key national highway near Bharatpur, fearing fresh trouble on the route.
Loads of people proudly claim themselves to be Gujjars in Pakistan. Do they belong to this same group?
**Tribesmen try to paralyse Delhi **
The protestors are demanding inclusion in affirmative action quotas
Thousands of protesters from India’s Gujjar tribe have burnt tyres and blocked key roads into Delhi in support of their demand for better treatment.
Tens of thousands of paramilitary troops and policemen have been deployed to maintain order.
Over the past week, at least 41 people have died in clashes between police and Gujjars in Rajasthan, western India.
The Gujjars are a large and politically influential tribe spread across the north of the country.
Meanwhile, in protests elsewhere, a member of the Gujjar community has been killed in Samalakha village in the state of Haryana.
Police said the man was killed when police fired rubber bullets at a crowd of protestors.
Protests have also been continuing in the state of Rajasthan.
Earlier this month the Rajasthan government announced an aid package worth $60m (£30m) for the community but this was rejected.
The Gujjars say they want to be placed on an official list of disadvantaged tribal groups that benefit from preferential recruitment to government jobs and educational institutions. Traffic blocked
Thousands of Gujjars have gathered on the outskirts of Delhi, chanting slogans against the chief minister of Rajasthan, Vasundhara Raje Scindia.
“They fired at Gujjars in Rajasthan. But it hurts Gujjars all over the country. We all stand united on the issue,” a Gujjar leader, Joginder Singh Awana, told the BBC.
“We want a case registered against the Rajasthan chief minister. She is a murderer. Forty of our people were shot and killed on her orders,” said an angry protester.
“When a terrorist is killed in an encounter, the human rights groups come out in his support. Dozens of unarmed Gujjars have been killed, but how come no one has come out in their support?” asked another.
On the outskirts of Delhi, traffic has been blocked by hundreds of Gujjars on the highway that connects the suburbs of Noida and Ghaziabad with Delhi.
Traffic jams have also been reported on the Mehrauli-Gurgaon highway that connects Delhi with Gurgaon.
Noida and Gurgaon are home to hundreds of call centres and IT offices.
The authorities have put Delhi and its suburbs, which make up India’s National Capital Region, on high alert.
Additional police have been deployed at all entry points and police check posts have been erected across the city.
The Gujjars have also threatened to stop essential supplies, including milk and vegetables, from coming into the city.
The violence began last Friday when police opened fire on Gujjar demonstrators in Rajasthan. Ever since, the protesters have blocked rail and road access between Rajasthan and Delhi, and a major highway linking the Rajasthan capital, Jaipur, to the city of Agra, which is home to the Taj Mahal. Last year at least 26 people were killed in similar protests.