Three persons were killed and several others injured in a blast near the venue of Trinamool Congress leader Abhishek Banerjee’s rally in West Bengal’s Purba Medinipur district, the police said on Saturday, according to PTI.

“The cause of the blast is yet to be ascertained and further investigation is underway,” an undentified police official said. “The impact was so powerful that the mud house with a thatched roof was blown off in the incident.”

The dead have been identified as Rajkumar Manna, reportedly a Trinamool Congress worker, Debkumar Manna and Biswajit Gayen, the officer added.

Leader of Opposition in West Bengal Suvendu Adhikari demanded an inquiry by the National Investigation Agency.

He alleged that the persons who died were making bombs that were to be hurled at the rally.

BJP national Vice President Dilip Ghosh claimed that the Trinamool Congress was responsible for the explosion and further alleged that “only bomb-making industry is flourishing in the state”, PTI reported.

Senior Communist Party of India (Marxist) leader Sujan Chakraborty questioned Chief Minister Mamata Banerjee’s silence on the blast.

Trinamool Congress state General Secretary Kunal Ghosh said it is very easy for the Opposition to blame the ruling party without proof.