A district-level BJP leader and three associates have been arrested after they allegedly beat a cab driver, Aqueel Ahmad, to death on a crowded fairground in Lakhimpur Kheri but the police have invoked charges of causing death by negligence rather than murder.

Relatives and neighbours of Aqueel, 28, staged a dharna after Wednesday’s arrests, castigating the police for invoking lesser charges carrying a maximum punishment of two years and questioning the force’s account of a brawl resulting in death.

Anup Shukla, former BJP district vice-president and currently chairman of the district cooperative federation — which advises the government on agriculture and other issues — has been arrested with Devarshi Shukla, Brajesh Shukla and Rajat Rastogi.

Chunnan and Suhel Baba Khan, two friends of Aqueel, had run away from the spot after the four assailants attacked the taxi driver on Tuesday, police said, adding that only fists were used. Aqueel died in hospital the same evening.

“The accused have said Devarshi had argued with Aqueel over a swing ride at the Vilobi Memorial Fair, a local festival,” Lakhimpur Kheri additional superintendent of police Arun Kumar Singh said. “Devarshi called his uncle Anup. Aqueel’s friends escaped while Anup and three others attacked him so badly that he died of his injuries. We checked the CCTV footage, identified the accused and arrested them.”

Sharif Ahmad, Aqueel’s elder brother, was unconvinced by the police’s explanation of the motive.

“The case may not be as simple as the police say. It should be investigated what led them to kill my brother,” he said. He added: “The police arrested the accused after 24 hours on the charges of rioting, unlawful assembly, voluntarily causing hurt (323), intentional insult and causing death by negligence. We want them booked for murder.”

The punishment for murder is death or a life sentence.

Chandrashekhar Singh, the officer in charge of the local police station, said: “We have assured the people that the section 302 (murder) may be added after inquiry.”

A senior BJP leader in Lakhimpur Kheri, speaking on the condition of anonymity, told reporters: “Anup and the others didn’t want to kill Aqueel. Rastogi hit him on the back. Aqueel slumped to the ground and later died in hospital.”

He added: “Unfortunately, the police arrested them and also released their pictures as criminals even though there is a BJP government in the state.”

After the arrests, some journalists had asked for pictures of the accused and the police had obliged.

Anup and the three other accused are real estate agents by profession.