JANAKPURDHAM: Three persons were killed in a bomb explosion in Kshireshwarnath Municipality-5, Dhanusha, on Friday midnight. A father and son duo along with a police inspector lost their lives in the incident. Rajesh Shah (42) and his son Ananta Shah (17) died on the spot when the improvised explosive device (IED) planted at the entrance gate of their home exploded at around 11:45 pm. Police Inspector Amir Dahal, incharge of Sakhuwa Mahendranagar-based Area Police Office, was injured in the same incident but died during the course of treatment. Rajesh's father Bhikhari Shah (73), his daughter Nikki Shah (21), son Prakash Shah (14) and another police personnel Rijan Mahatto were injured in the incident. Bhikhari Shah is undergoing treatment at Janakpur Zonal Hospital while others are being treated at BP Koirala Institute of Health Sciences, Dharan. Locals believe that deceased Rajesh Shah was informed about the pressure cooker bomb at his house through a phone call. On receiving the call, Rajesh along with his family had moved out of the house and were staying 300 metres away at his brother Raj Kumar Shah's house. After the information was given to the police, a team of security personnel tried to check the bag when the IED exploded, injuring Police Inspector Dahal. The reason behind planting the IED is yet unclear. An investigation into the incident is underway, police said.