Polling is underway on Saturday in two assembly seats in Chhattisgarh that were earlier won by the Bahujan Samaj Party (BSP) and Congress.
Balloting began on a slow note before catching up in Khairagarh in Rajnandgaon district and Malkharoda in Bilaspur district.
Central Reserve Police Force (CRPF) personnel were deployed in large numbers in Khairagarh where the ruling Bharatiya Janta Party (BJP) is locked in a fight with the Congress.
In Malkharoda, the BSP has an edge over the Congress and BJP.
The election in Malkharoda was necessitated after the court disqualified BSP legislator Lalsai Khunte because he hid information regarding his conviction in a criminal case when he filed nomination papers in November 2003.
The party has fielded Khunte again as the court later acquitted him.
In Khairagarh, the election followed Congress legislator Devrat Singh's election to the Lok Sabha from Rajnandgaon in April this year. The results for the by-polls are to be announced on June 5.