The incident occurred at Danra Bapuji Chak Primary School in Maya Hauli village under Jaynagar police station at about 8.30 PM when there were about 300 people in the queue.
Amal Haldar, who was in the queue went to a jawan to ask something, but the securityman opened fire killing him on the spot, the sources said.
Language problem could be the cause of the incident following which the polling process stopped there, the sources said.
Top district officials have reached the spot.