A violent clash involving throwing of crude bombs between two groups —allegedly backed by rival Trinamool Congress (TMC) factions — over control of illegal sand mining operations broke out on Tuesday in Birbhum’s Kankartala area.

The clash allegedly stemmed from a struggle for control over the proceeds from an illegal sand mine in the Ajay river area of Jamalpur, Kankartala. Local sources alleged the fight was also about “establishing dominance” in sand extraction from the river.

A man, identified as Sheikh Saktar Ali, sustained serious injuries in the incident, with administration officials confirming the amputation of his right leg. Ten people have been arrested, including Saktar, who is undergoing treatment. The others are in police custody.

The police said another person was also injured in the clash.

Residents have long complained about the alleged illegal sand extraction from the Ajay river, accusing “local TMC goons” of the activity. The incident comes a month after Chief Minister Mamata Banerjee reprimanded district magistrate Bidhan Ray during a live-streamed administrative meeting over sand smuggling in Birbhum.

BJP MLA and senior party leader Anup Saha said, “People from Anubrata Mondal and Sheikh Kajal’s factions clashed with bombs over extorting money from sand mines. We condemn such extortion practices in the TMC.”

Mondal, recently released on bail in a cattle smuggling case, is reportedly a rival of Kajal — who gained prominence in the district during Mondal’s imprisonment.

The TMC, however, has distanced itself from the violence. “Our party has nothing to do with this clash or the practice of extortion. The police will take action against those involved. It may be that the clash broke out between rival groups of goons over some local issues,” said TMC district vice-president Malay Mukherjee.