Guwahati, Apr 9 (IANS): Voting was underway at a brisk pace on Sunday in the by-election to the Assam assembly from the Dhemaji constituency, officials said.

People in large numbers queued up at the polling stations well before voting started at 7 a.m.

"Polling is going on smoothly and 43.5 percent have voted by 1.00 p.m. from across 273 polling booths," Dhemaji Returning Officer Roshni Aparanji Korati said.

She said the Voter Verifiable Paper Audit Trial (VVPAT) machines were used in polls for the first time in the state.

Of the 2,19,751 voters, 1,07,241 are females.

Adequate security forces have been deployed to ensure free and fair poll, Korati said, adding 20 polling stations have been marked as "very sensitive" and 141 others as "sensitive".

The by-poll was necessitated following the election of Bharatiya Janata Party (BJP) lawmaker Pradan Baruah as member of Parliament from the Lakhimpur constituency after Assam Chief Minister Sarbananda Sonowal resigned from his parliamentary seat.

Five candidates are in the fray but the main contest is likely to take place between ruling BJP candidate Ranoj Pegu and Congress party nominee Babul Sonowal.

The other three candidates are Communist Party of India-Marxist's Jadu Hazarika, Socialist Unity Centre of India-Communist's Hem Kanta Miri and Independent Rajkumar Doley.