The clash took place in Rahariya village over a piece of land having a lake between Mahadalit people and some land owners after both claimed its ownership, Forbesganj SDPO Ajit Singh said.
The Mahadalits allegedly attacked land owners' houses with bows and arrows and torched three two-wheelers before some people on behalf of land owners overpowered an elderly Mahadalit Kamleshwari Rishidev (55) and local CPI (M-L Liberation) leader Satya Narayan Yadav (45) and had their hands and legs chopped off with sharp objects, he said.
The landowners' men also attacked other Mahadalit people injuring four of them, identified as Bipin Rishidev, Ramchandra Rishidev, Bachan Rishidev and Sriram Rishidev, the SDPO said.
The injured persons have been admitted to a primary health centre, he said.
An FIR has been lodged in this connection and raids were being carried out to nab the culprits.
Additional policemen have been deployed in the village in view of tension prevailing there, the SDPO said.