The human sacrifice took place Thursday night at Narayanpur basti - a locality where inhabitants are mainly labourers on nearby tea plantations. The village, adjacent to Narayanpur tea estate, falls within the jurisdiction of Lakhipur police station in Cachar district, over 300 km from the state capital.
Cachar district Superintendent of Police Diganta Bora said there was suspicion this was a case of witch-hunting.
Quoting local people, Bora said: "One of the residents of the village said he saw Devi Maa (a goddess) in his dream. He said the goddess told him that Jawaharlal Mura, a fellow-villager, was possessed by evil spirits and that the entire village would suffer if he stayed in the village."
"The man shared his dream with others in the village, and a group of men caught hold of Jawaharlal Mura. They tied him to a tree and tortured him, offering prayers to appease the goddess. Mura died," Bora explained. Later, the people who performed the ritual buried him and warned villagers of dire consequences if they complained to the police.
Bora said police were, however, informed.
"We got the information last night, but we did not want to enter the area at night, when many of the tea labourers are drunk and could cause major law and order problems," Bora said.
Bora said a police team entered the village Friday morning and managed to retrieve the body of the victim, which was sent for autopsy. Police resorted to lathi charge to disperse a mob that had gathered at the spot.
The 11 arrested are still to be interrogated by state police.
The practice of witch hunting is common among some communities in Assam, including the Adivasis and tibals once largely associated with work on tea gardens.
Assam Police in 2001 launched "Project Prahari" (Project Watch) to encourage participatory development and people-friendly policing. Under the project, an awareness drive was also launched against "witch-hunting".