As many as 14 crude bombs were recovered at the Shamsherganj area of poll-bound West Bengal's Murshidabad district on Monday.
Later, the bombs were disposed of by the Bomb Disposal Squad.
The incident came into light ahead of the fifth phase of assembly polls in the state on April 17.
Earlier on April 10, violence erupted at a polling booth in Cooch Behar during the fourth round of polling. The ruling TMC alleged that Central forces opened fire twice at polling booths in Cooch Behar where people are casting their votes, killing four party workers.
Official sources in Cooch Behar confirmed the death of four people in the district.
Following the incident, the EC ordered the adjourning of the poll in PS 126 of Sitalkurchi AC, Cooch Behar based on an interim report from Special Observers. The EC will seek a detailed report from them and the Chief Election Officer by 5 pm on Saturday.
Since the incident, the Election Commission has barred the entry of any political leader in the Cooch Behar district for the next 72 hours.
Polling for the first four phases has been concluded in West Bengal. The fifth and sixth phases of the ongoing elections will take place on April 17 and April 22. The counting of votes will take place on May 2.