A two-year-old child died and his six-year-old relative suffered critical injuries when a neighbour who used to feel disturbed by their playful mischief allegedly threw them off the fourth-floor balcony of a Burrabazar building on Sunday evening.

Shivam Sau, 2, was playing with his uncle Vishal, 6, and four-year-old sister on the shared balcony of the building around 6pm when Shiv Kumar Gupta, 55, a real-estate broker who also runs a small transport business and lives on the same floor, lunged at them, according to the four-year-old whose name could not be ascertained.

Gupta has been arrested and charged with murder, police said.

The police’s preliminary inquiry has revealed that Gupta used to frequently complain to the Saus about the children knocking on his door and waking him from sleep.

The police and neighbours said Gupta would also feel disturbed if a ball entered his room while the kids played on the balcony. The police said they did not yet know if any such thing had happened on Sunday.

According to Shivam’s sister, Gupta first lifted Shivam, the youngest of the trio, and threw him off the balcony. He then allegedly grabbed Shivam’s sister but she managed to wriggle out and run away. But before she could alert her parents, Gupta allegedly got hold of Vishal and threw him down too, neighbour Rima Yadav quoted Shivam’s grandfather Budhan Sau as saying.

Apart from Shivam’s sister appearing to have witnessed the alleged crime, the height of the balcony railings would make it unlikely for children so small to accidentally fall off.

“I heard loud cries in the evening and rushed to the balcony fearing the building was collapsing. But then I heard Shivam’s mother cry out that her son had been thrown off the balcony. I spotted Vishal lying on the asbestos shade attached to my balcony. I realised that Shivam had fallen a few metres away, on the road,” said Rima, who lives on the first floor.

Rima added that she did not witness the crime but heard about it from Shivam’s grandfather Budhan.

Shivam’s father, Vikram Sau, drives a goods vehicle. The family hails from Begusarai in Bihar and has been living at 113 NS Road in Burrabazar for close to 10 years, neighbours said.

The police said that a fortnight ago, Gupta had objected to the children knocking on his door while he slept.

Budhan has two sons. Shivam and his sister are children of Budhan’s elder son Vikram. Vishal, the critically injured child, is Budhan’s younger son.

Gupta has four sons, two of whom had travelled to the family’s ancestral home in Varanasi before the lockdown.

“He (Gupta) has a granddaughter who is very small like the (Sau) children. It’s shocking how he could do this. His younger son had gone to the market to buy vegetables. When he returned, the police had already taken his father into custody,” a neighbour said.