No untoward incident was reported as an electorate of over 17,000 will vote to determine the fate of seven candidates, Returning Officer for the by-poll A. Biaklawma told PTI.
He said that 13 polling stations have been identified as 'sensitive'.
The polling would continue till 5 PM.
The seven candidates are Dr Ngurdingliana of the ruling Congress, Lalvenhima Hmar of the opposition Mizo National Front (MNF), Lalhmangaiha Sailo of the Mizoram People's Conference (MPC), C. Lalchhandama of the Zoram Nationalist Party, C. Ramkinlova of the BJP, D.K. Thanga of the Lok Janshakti Party (LJP) and lone independent R. Lalrohlua.