NEW DELHI (Agencies) - The Naxals in four Indian states killed at least 20 persons during the first phase of Lok Sabha polls held on Thursday. As the polls began on Thursday morning, the Naxals struck at several points in the Jharkhand, Chhattisgarh , Bihar and Orissa states setting on fire polling booths, killing security persons and attacking election staff. In Jharkhand a bus carrying Border Security Force personnel hit a landmine, killing seven personnel and two civilians. In Chhattisgarh, a poll vehicle was blown up killing five persons while during a gunbattle two security personnel were also killed. Similarly, in Orissa and Bihar, Naxals attacked polling booths leaving several security personnel dead. Deputy Election Commissioner R Balakrishnan while briefing newsmen on the polls admitted that out of 1.85 lakh polling stations involved in the elections, 76,000 polling stations came under some degree of Naxal threat. Voting was disrupted at 86 polling stations, 71 of them by Naxals, he said. He claimed the elections were largely peaceful. He said the polling percentage ranged from 46 per cent in Bihar to 86 per cent in Lakshadweep. During the first phase of the five-phased polls, voting was held in 124 constituencies of fifteen states and two union territories including Kerala, Chhattisgarh, Arunachal Pradesh, Meghalaya, Bihar, Uttar Pradesh, Maharashtra, Andhra Pradesh, Jharkhand, Orissa , Assam , Manipur, and Occupied Kashmir. There were 1,715 candidates are in the field. Tens of millions voted Thursday as the worlds largest democracy kicked off month-long, five-stage elections, with little hope of a clear winner emerging at the end of it all. From the southern tropical state of Kerala to the Himalayan foothills of Occupied Kashmir in the north, they cast their ballots at the start of a process so complex and spread out that six million civil and security personnel are needed to keep it on track. Neither the ruling Congress party nor its main rival, the Hindu nationalist Bharatiya Janata Party (BJP), is expected to win outright when voting wraps up on May 13, setting the stage for some old-fashioned political horse-trading to build a coalition that can govern Indias one billion people. The election comes at a pivotal time for India and its 714 million electorate, with a once red-hot economy feeling the strain of the global downturn and relations with neighbouring Pakistan at a new low since the deadly Mumbai attacks in November. Domestic security concerns were highlighted soon after polling opened when Maoist rebels launched attacks in several eastern states, killing at least 19 people, including 10 paramilitary troopers and five election workers. The Maoists, who say they are fighting for the rights of neglected tribal people and landless farmers, have been described by Prime Minister Manmohan Singh as the biggest overall threat to Indias stability. Elsewhere, patient voters formed long and often colourful queues to use the electronic voting machines and have their fingers stained with indelible ink to prevent any fraud. Many voters are also expected to make their choices along purely religious and caste lines, making the final result almost impossible to predict. In the inevitable rush to cobble together a post-poll coalition, both national parties will be looking to the tactical skills of their veteran leaders: Manmohan Singh, 76, for the Congress and the BJPs LK Advani, 81. Our kids are so desperate for food, said Ruksana Begun, as she cast her ballot in Varanasi, with only her eyes visible from under an all-enveloping black burka. Everything is expensive and the people here are very distressed by the prices, she said. After five successive years of near-double-digit growth which lent the country the international clout it has long sought, the economy has been badly hit by the global downturn. Voters in Kashmir cast their ballots under tight security in elections clouded by a warning by freedom movement leaders that anyone taking part would be branded a 'traitor'. Voting in Occupied Kashmir, where an insurgency against Indian rule has claimed 47,000 lives in the past 20 years, has been split into five stages to provide maximum security at the polling booths. Thursdays polling was held in the states Hindu-dominated Jammu and the districts of Rajouri and Poonch. Army troops, backed by tens of thousands of police and paramilitary personnel, were deployed in the streets and outside polling booths.