New Delhi - At least five policemen were on Tuesday killed in a landmine blast triggered by suspected Maoist rebels in India's central state of Chhattisgarh, a news report said.

The explosion that took place in the southern Bastar district of the state blew up a bridge killing five policemen and injuring two other security personnel, the PTI news agency reported quoting senior police official AN Upadhya.

The rebels carried out the blast when the policemen were returning after their election duty at polling booths in the region.

Chhattisgarh is one of the six Indian states holding elections.

Senior police officials and additional police forces have been sent to the region, considered a hotbed of Maoist militancy.

Maoist militants, who claim to be fighting for the rural poor, operate in 13 of India's 29 states. They usually target police and government installations.

According to independent estimates, over 500 people - including civilians, police and rebels - have been killed in Maoist violence in India since the beginning of the year. (dpa)