Polling began on Monday morning amid unprecedented security for the one-day election to the 234-member Tamil Nadu assembly.

Coverage: Assembly Elections 2006

In some booths, people were seen queuing up from 6.45 am. Tight security arrangements have been made for the elections and 198 companies of paramilitary forces have been deployed along with the state police to prevent any untoward incidents.

In the city, police have deployed 15,000 of their personnel besides 1500 paramilitary forces.

Official sources said over 3,300 booths, spread over 60 constituencies, have been identified as sensitive depending on the candidates in the fray, caste or religious conflicts prevailing in the area. Nearly three lakh personnel will be on duty in 51,534 polling stations.

The state has 4.63 crore voters who will choose from the 2,586 candidates in the fray.

The ruling All India Anna Dravida Munnetra Kazhagam, leading the Democratic People's Alliance, is contesting 182 seats, leaving 35 to Marumalarchi Dravida Munnetra Kazhagam, nine to Dalit Panthers of India and the remaining among various smaller allies.

In the opposition Democratic Progressive Alliance, the Dravida Munnetra Kazhagam, heading the alliance, is contesting 130 seats. Congress has been given 48 seats while Communist Party of India (Marxist) has been given 13, Communist Party of India 10 and Indian Union Muslim League two.

The Bharatiya Janata Party and actor-turned-politician Vijayakanth's Desiya Murpokku Dravida Kazhagam, making electoral debut, are contesting the elections on their own.

The polling which began at 7 am, will end at 5 pm.