“Tribals are one of the most landless communities in India,” said Kumar Sambhav Shrivastava, a journalist and co-founder of Land Conflict Watch, a data project that analyzes these disputes. “Traditionally, it was easy to take over their land, kick them out.”

The authorities said that all of the people killed on Wednesday — seven men and three women — were Gond members, and that some Gujjar men had also been injured in the fighting. The police said the combatants also used wooden sticks, cleavers, spades and iron rods.

Police officials said that they had arrested 24 people in connection with the violence, but that the village chief was still at large.

Gujjars are hardly at the top of the overall caste ladder, and are far below the Brahmins, who are considered the highest. In some places, Gujjars complain that they themselves are discriminated against because of their caste. But in Sonbhadra District, they own much of the land.

Competition for land in India is sometimes so fierce that living men have been formally declared dead by competing relatives eager to inherit their plots. They bank on a byzantine court system taking years to correct the error.

Vijay Singh Gond, a former state lawmaker in Sonbhadra District, said the situation was so desperate in his area that “land sharks” were circumventing laws that restrict the amount of land one person can hold by putting their pets’ names on titles.

“Landlords in that area own land in the names of their dogs, cats and even under the names of trees and plants,” he said.