In a major blow to India's election, at least 15 people, including security personnel and election officials, were killed Saturday in land mine attacks by left-wing rebels in central India, said police.
This is the second deadly attack by the Naxalite rebels who killed two policemen on Thursday in the eastern state of Bihar during the polling.
Otherwise, the election has held four phases so far in a generally peaceful atmosphere and high turnouts.
The government has deployed thousands of security personnel in five worst rebel-infested states of Chattisgarh, Jharkhand, Orissa, Bihar and West Bengal during the election which is expected to last until early May.
The rebels have threatened all voters who might participate in polling and vowed to attack security forces and election officials wherever and whenever possible.
Saturday's first attack took place near Darbha in the state's Jagdalpur district when the rebels attacked an emergency vehicle carrying some eight para-military troopers. The second attack took place in Bijapur district where a group of armed Naxalites blew up a bus carrying a number of election officials who were returning from polling duty.
Both attacks took place in the Naxalite-infested Bastar region where peaceful polls were held just two days back and witnessed a moderate turnout despite a boycott call by the Naxalites.
A massive manhunt has been launched to track down those responsible for the two attacks during the general elections in the country.
Prime Minister Manmohan Singh has described Naxalite insurgency as the country's biggest internal security threat.
The rebels have changed their guerrilla attack tactics this time by targeting poll party while they were returning after polls. Earlier, they would attack polling parties and security forces before polls or on polling day in an effort to disrupt elections, said Times of India online.
Security experts said that once polling is over in a constituency, poll parties and security forces tend to become complacent over security and rebels used the situation to their advantage to strike at them at an unsuspecting area, said the newspaper.
Security personnel deployed in rebel-infested areas are not supposed to use vehicles in view of possibility of landmine attacks.
Chattisgharh Chief minister Raman Singh has strongly condemned the killings, describing it as an act of cowardice. A group of Bharatiya Janata Party and its youth wing members took out demonstrations and burnt effigies of Naxalism at different places protesting against the killings.
Saturday's attacks also highlighted the seriousness of the Naxalite rebel problem for India despite the government estimation of decline of the activities of the rebels, who have been attacking government and security forces for over four decades in poor rural areas.)