Kalyani, April 11 An improvised explosive device detonated on the rooftop of a school building in the Nadia district of West Bengal, a state heading to elections, on Saturday, police said.
No casualties were reported in the incident that occurred at the Ghordagacha Madhyamik Shiksha Kendra in the Saguna panchayat area within the Kalyani assembly constituency.
The blast took place shortly after school hours, when students had left the premises following an examination. A few teachers and non-teaching staff were still present when the loud explosion was heard from the rooftop, they added.
Teachers rushed upstairs and found that an improvised explosive device had detonated, while another unexploded device was lying nearby. Police were immediately informed.
Sub-Divisional Officer (SDO) of Kalyani, Pritam Saha, said that an investigation is underway.
Election Commission general observer for Kalyani, P Siva Sankar, visited the spot for inspection, accompanied by security forces.
The TMC accused BJP workers of planting the explosives to create unrest ahead of the polls, while the BJP denied the allegation and blamed the ruling party.
West Bengal will go to the polls in two phases, on April 23 and 29. The votes will be counted on May 4.