New Delhi - At least four policemen were killed Monday in a landmine blast triggered by suspected Maoist rebels in India's central state of Chhattisgarh during a visit by President Pratibha Patil to the region, news reports said. 

The incident occurred in a forested region in the Bastar district, 350 kilometres south of state capital Raipur, when a police team was on a patrol to secure the region for the visit of the president, the NDTV network said. 

Patil was visiting a waterfall in the picturesque Chitrakoot area, located some 30 kilometres away from the blast site, and later returned to Raipur, the report said. 

Local police told the NDTV said the rebels blew up a jeep in a forested area, killing Central Reserve Police Force officer Diwakar Mahapatra and another policeman on the scene. 

Two wounded policemen succumbed to their injuries on the way to the hospital. 

Five injured policemen were being treated at a government-run medical facility in the region, which is considered a hotbed of Maoist militants. 

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, more than 400 people, including civilians, policemen and rebels, have been killed in Maoist violence in India since the beginning of the year. 

Indian Home Secretary Madhukar Gupta recently announced that six jungle warfare and counter-insurgency schools would be set up to train security personnel to combat the rebels. (dpa)