Four persons were arrested on Sunday for their alleged involvement in the murder of nine-year-old Swarnabha Biswas in Tehatta of Nadia district.

The tragic incident triggered mob violence on Saturday, causing a couple in the neighbourhood, Utpal and Soma Mondal, to get lynched on suspicion of the child’s murder. The couple’s daughter-in-law Nisha was also severely beaten up.

On Sunday, one person was arrested in the lynching case.

Swarnabha, a resident of Jhautala-Nischintapur in Tehatta, went missing on Friday afternoon. His body, wrapped in a plastic sheet, was found in a ditch near the Mondals’ house on Saturday morning.

The mob claimed the couple had abducted Swarnabha with the intention of trafficking him and murdered him when his family started searching for him.

Following the violence, police initiated a suo motu investigation against around 200 unidentified persons who formed the mob.

A day after the lynchings, police arrested the deceased couple’s son Chhottu Mondal, along with their relatives Supriya Bhowmik, Kartick Mondal and Suchitra Mondal, based on a complaint lodged by Swarnabha’s father, Satyen Biswas.

“Based on the complaint by the child’s father, we have so far arrested four persons. They were produced before a court in Tehatta. Investigations are underway for both the back-to-back incidents—the murder of the child and the lynching of the couple. We have assured people of stern action against all involved and maintaining police presence in the locality,” said additional superintendent (rural) of Krishnagar police district Uttam Ghosh.

Police sources said that after being produced before the additional chief judicial magistrate’s court in Tehatta, the four arrested individuals were remanded to 10 days in police custody.

Later on Sunday afternoon, police arrested a person, Soumyajit Biswas, in connection with the lynching incident of Saturday.

“In connection with the suo motu case begun by the police for the lynching incident, one person named Soumyajit Biswas alias Bubai, named in the FIR been arrested,” said Ghosh.

Soumyajit will be forwarded to court on Monday.

“We will seek 14 days of police remand for him,” added Ghosh, the additional superintendent (rural) of Krishnanagar police district.

Police picketing has been reinforced in and around the site of the lynching as well as at the residence of the lynched couple, where the child had been allegedly killed.

However, investigators have not made any headway in discovering the motive behind the child’s murder. The prime accused — the couple — are dead. No clue corroborating the suspected trafficking angle has emerged.

However, police are hopeful of unravelling the mystery while interrogating the four accused persons incustody.

A day after the violence, Jhautala-Nischintapur wore a deserted look.

Most of the men have fled the village, fearing police action over their suspected involvement in the lynching incident, sources said.