Voting began at 7 AM and expected to conclude at 6 PM.
Polling for Dubbak Assembly by-poll got underway on Tuesday with voters queuing up outside the booths to exercise their franchise.
Voting Dubbak (in Siddipet district), around 100 km from Hyderabad, began at 7 AM and expected to conclude at 6 PM at 315 polling stations.
The district administration has made arrangements in compliance with COVID-19 protocols, besides tight security measures, officials said.
Nearly 2,000 personnel comprising central forces and Telangana police have been deployed as part of security arrangements for smooth conduct of the by-polls, a senior police official told PTI.
Sufficient arrangements have been made and different teams, including flying squads, surveillance, patrolling were formed to ensure peaceful by-elections, the official said adding a total of 1,317 people were already bound over.
Though 20 others are also in the fray, the main contest is among the candidates of the TRS, BJP and Congress.
The bypoll is necessitated by the death of sitting TRS MLA Solipeta Ramalinga Reddy due to health problems in August this year. The ruling TRS has fielded his widow Solipeta Sujatha as its candidate.
The Congress has fielded Cheruku Srinivas Reddy, who defected to the party from TRS, just ahead of the bypoll.
Congress is banking on the goodwill of Srinivas Reddy's late father Mutyam Reddy, a former minister.
The BJP, meanwhile, has given its ticket to M Raghunandan Rao, who lost in Dubbak in the previous Assembly elections.
The party hopes to ride on the popularity of Prime Minister Narendra Modi.
The total number of voters in Dubbak assembly constituency is 1,98,756, including 1,00,778 female and 97,978 are male.
The campaign witnessed a war of words between the ruling TRS and opposition BJP over allegations of money being seized from the candidate of the saffron party.
The counting of votes will be taken up on November 10.