Leftist extremist groups are "very active" in wide areas of impoverished rural eastern and Central India, the US State Depaftment has said.

The Maoists also operate in parts of southern India, the State Department said in its latest annual report on terrorism.

It said hundreds of people were killed in conflicts between the government and various leftist extremist groups, such as Naxalites and the Communist Party of India (Maoists), and also in internecine war.

"The Government of India is very concerned over the threat from leftist extremist groups to internal stability and democratic culture," it said