Counting of votes began at 8 am on Thursday amid tight security in polling centres in three Assembly seats of West Bengal where bypolls were held on November 25, Election Commission officials said.

Around 78 per cent of over seven lakh electorate had cast their votes in the by-polls to Kaliaganj, Karimpur and Kharagpur Sadar Assembly seats where 18 candidates were in the fray.

BJP state vice-president and the party's candidate in Karimpur, Jay Prakash Majumdar, was assaulted during polling in the constituency.

The Kharagpur Sadar and Karimpur seats fell vacant after the general elections as the sitting MLAs of the two seats Dilip Ghosh (BJP) and Mahua Moitra (TMC) had contested and won Lok Sabha seats.

The by-poll at Kaliaganj was necessitated following the death of Congress MLA Parmathanath Roy.

Congress nominee Dhitashree Roy, supported by the CPI(M), is pitted against TMC's Tapan Deb Sinha and BJP's Kamal Chandra Sarkar at Kaliaganj.

In Karimpur the CPI(M)-Congress candidate Gholam Rabbi is in the reckoning against Majumdar and the ruling TMC's Bimalendu Singha Roy.

In Kharagpur Sadar the contestants are Prem Chandra Jha of BJP, Chittaranjan Mandal of the Congress-CPI(M) alliance and Pradip Sarkar of the TMC.