The by-elections would be held amid tight security arrangements in the presence of adequate central forces and state police personnel, state's Chief Electoral Officer Sunil Gupta told PTI.
Eleven candidates, including two women, are contesting the by-election to the Bongaon (SC) Lok Sabha seat in North 24-Paraganas district, bordering Bangladesh.
For the by-election to the Krishnaganj (SC) Assembly seat in Nadia district, five candidates are in the fray.
The by-elections will be held in 1,863 polling stations in Bongaon Parliamentary seat and in 288 polling stations in Krishnaganj Assembly seat, the CEO said, adding, polling personnel have already reached their respective polling stations with polling material.
Gupta also said strong surveillance via video cameras and mobile units of the EC would be in place under the guidance of election observers during the polling process.