 "A third of voters cast ballot in Chhattisgarh")
By 1 p.m., between 30 to 35% votes were cast, election officials said.
Union Home Minister Sushilkumar Shinde said in New Delhi: "Situation in Chhattisgarh is fully under control, there are long lines since morning."
"Even in places where we had concerns, polling is taking place smoothly," he said.
A total of 143 candidates are in the fray Monday, their fate to be decided by about 2.9 million voters.
The sprawling region that went to the polls Monday includes Bastar, which with around 40,000 sq km is bigger than the size of Kerala, and the neighbouring Rajnandgaon district.
Bastar accounts for 12 assembly constituencies and Rajnandgaon six. Together, this mineral rich area -- with dense forests and Maoist hideouts -- is infamously known as the red zone.
More From This Section
Polling was suspended for 10-15 minutes at a polling booth in Dantewada district after suspected Maoists opened fire.
A Border Security Force (BSF) trooper was injured in a bomb blast in Kanker district while a bomb weighing about 10 kg was recovered in Bijapur, police said.
There was tight security for the first phase polling for the 12 seats in Bastar division and the six seats in Rajnandgaon district.
Total 4,142 polling booths have been set up across the 18 assembly constituencies. Among these, 1,311 are hypersensitive and 1,517 are sensitive.
Director General of Police Ramnivas said that 15 IEDs have been recovered from different parts of Bastar region.
Maoists disrupted voting in forest areas at nine polling booths in Bijapur, Sukma, Konta and Antagarh assembly constituencies.
Chief Minister Raman Singh, who is looking for a third term, told TV channels that there was high percentage of voting. He said there was "enthusiasm" among voters which was a "good sign for the BJP".
Congress and Bharatiya Janata Party (BJP) workers clashed in Jagdalpur and Konta assembly constituencies. Congress candidate from Jagdalpur Samu Kashyap was injured in the clash and was taken to hospital.
Polling for 18 assembly seats in Chhattisgarh's Maoist strongholds, began early Monday on a dull note as several polling booths in the forested interiors were deserted, but the pace picked up as the day progressed.
The 'None of The Above' (NOTA) option, widely called 'Right to Reject', is also making its debut in India in the Chhattisgarh polls.
Voting began for 13 seats at 7 a.m. sharp while it started at 8 a.m. for the remaining five seats. The majority of polling booths in the forested areas of Bastar wore a deserted look in the early hours.
Voting in constituencies where polling began at 7 a.m. will end at 3 p.m. so that polling officials can return safely from Maoist areas by sunset.
In urban areas such as Jagdalpur town, Kanker and in Rajnandgaon city, polling began at a brisk pace and long queues were seen at several booths.
In Rajnandgaon, where BJP candidate and Chief Minister Raman Singh is contesting, women and youth could be seen queuing up at polling booths.