As the voting exercise began by 7 am, women outnumbered men in a handful of polling stations.
Amid tight security, polling began in two Assembly constituencies in Tamil Nadu and one segment in neighbouring Puducherry as voters turned up enthusiastically to cast their votes early in the day.
As the voting exercise began by 7 am, women outnumbered men in a handful of polling stations at Vikravandi in Villupuram District and at Nanguneri in Tirunelveli district. Both youngsters and senior citizens showed equal interest in exercising their franchise.
AIADMK's M R Muthamizhselvan and Reddiyarpatti V Narayanan are in the fray in Vikravandi and Nanguneri segments respectively.
DMK's N Pugazhendhi is contesting from Vikravandi constituency and its ally Congress party's nominee ''Ruby'' Manoharan is testing his luck from Nanguneri.
In Puducherry's Kamaraj Nagar too voting is going on peacefully where the ruling Congress party's A John Kumar and the Opposition AINRC nominee S Bhuvaneswarane are locked in a direct fight.
All the 574 polling stations in Vikravandi (275) and Nanguneri (299) are covered by live web streaming.
In Vikravandi, 18 polling stations are "critical," and 32 "vulnerable."
As regards Nanguneri, there are no critical polling booths and there are 110 vulnerable stations.
While Vikravandi has an electorate of 2.57 lakh voters, Nanguneri has 2.23 lakh voters.
Over 3,000 personnel are on duty for the bypolls in Tamil Nadu.
About six companies of paramilitary forces are on the ground in the two segments for the byelections.
Kamaraj Nagar has 35,009 voters, and of the 32 polling stations there, seven are vulnerable. In addition to local police, one company of Central police forces has been deployed in the Union Territory.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)