123 Kolkata: A powerful explosion rocked a five-storey apartment building in Titagarhearly on Monday morning, triggering widespread panic among residents. Police suspect bombs were stored inside a closed fifth-floor flat of the apartment, leading to the blast that injured an eight-year-old boy and damaged nearby structures.Three persons, including the Trinamool Congress councillor Arman Mondal alias Rizuddin of Titagarh Municipality, and his two associates Arshad Khan and Mohammad Shahrukh were arrested on Monday afternoon in connection with the blast.The explosion, which occurred around 6.40 am near Banshbagan crossing at ward no. 4 in Titagarh Municipality, caused a portion of a wall to collapse and blew off the roof of an adjacent tiled house. Barrackpore Police Commissioner Ajay Kr Thakur told TOI, "Prima facie, it appears that bombs were stored in the closed flat, which led to the blast. Some residents are being interrogated, and an investigation is underway."Municipal sources confirmed the presence of several councillors in the building, amplifying the shock. The blast also damaged the water supply lines, leaving residents without water amid intense summer heat. "Residents have demanded immediate restoration of water and security assurance," said a senior civic official.The ground floor of the building was reportedly rented by local (TMC) councillor Arman Mondal, while the fifth-floor flat was leased to a promoter named Anil Kr Gupta. Gupta alleged that another TMC councillor, Mohammad Rizuddin, forcibly occupied the room since the last Lok Sabha elections. However, Rizuddin denied the allegations, calling it a "politically motivated conspiracy".Police are also examining the role of Arman Mondal, who sublet parts of the premises. "The origin and motive behind stockpiling explosives, if confirmed, will be crucial to the probe," a police source said.A thorough search operation is ongoing in and around the building.