India's Red Corridor is on high alert as the Maoists have called a two-day bandh to protest against government's Operation Greenhunt.

Four states - Jharkhand, West Bengal, Orissa and Chhattisgarh - have been put on alert.

Police are expecting trouble in Jharkhand as it goes to the polls on November 18.

Reports say two Maoist companies of 100 members each have fanned out in the Andhra, Orissa border.

Meanwhile the Naxals have blocked off Orissa's Narayan Patna in Koraput district as the two-day bandh begins.

They are demanding an immediate withdrawal of CRPF forces and the govt's Operation Greenhunt.

Security forces are on a high alert in Malkangiri, Koraput, Rayagada and Gajapati districts in South Orissa.

The Naxal sleeper cells have been most active in these districts over the last couple of weeks.

Also there are reports that a very large number of armed Naxals are hiding in the thick forests of south Orissa.