Police said the dispute over the plot had been going on for over five years and the two groups used swords and other sharp weapons during the clash, which took place at Matijuri area of Hailakandi district.
The dead persons have been identified as Mizanur Rahman Chaudhary (65), Nazimuddin Chaudhary (30), Nazrul Haq Barbhuiyan (35) and Aziruddin Barbhuiyan (40).
Additional police forces have been deployed in the area and search is on for the culprits.
The situation in the area is tense but under control, the police added.