A family of four, including two minor children, was burnt to death by some villagers in Katihar district of Bihar, allegedly over a land dispute, police said on Monday."Four people -- a married couple and their two minor children -- were burnt to death when they were sleeping in a room that was locked from the outside and set ablaze by unidentified people late Sunday night," Katihar Superintendent of Police Kshatranil Singh said.A local official said a case was lodged in this connection on the basis of some villagers' statements to police that they suspected a land dispute behind the incident."A preliminary investigation into the case suggests a land dispute was the cause," a police official said.No arrests have been made so far.The incident has created panic and anger among the villagers, who have protested and demanded the immediate arrest of the attackers.