A team of police raided the party office at Arambagh in the morning and seized the bombs, pistols and also some video clippings which would be examined later on, police said.
Ten party workers who were on the spot during the raid were also taken into custody. As the news went around in the locality, people along with Trinamool Congress activists gheraoed the office for sometime.
Opposition leader Suryakanta Mishra alleged that the police is acting at the behest of the Trinamool Congress led state government to bring disrepute to them.
"Our party is now getting support from the people and so the Trinamool is scared of us and therefore they are trying to manipulate things," he said.
District Trinamool Congress president and MLA Tapan Dasgupta said other offices of CPI(M) should also be raided similarly.
