India's bloody Maoist insurgency began in the remote forests of the state of West Bengal in the late 1960s.
Decades later Prime Minister Manmohan Singh described it as India's "greatest internal security challenge".
Maoists are also known as "Naxalites" because of the violent left-wing uprising in 1967, which began in the West Bengal village of Naxalbari.
Although this was eventually quashed by police, over the years India's Maoists have regrouped and asserted control over vast swathes of land in central and eastern India, establishing a so-called "red corridor".
This spans the states of Jharkand, West Bengal, Orissa, Bihar, Chhattisgarh and Andhra Pradesh and also reaches into Uttar Pradesh, and Karnataka.
The Maoists and affiliated groups are thought to control more than one third of India's 600-odd districts.
And more than 6,000 people have died in the rebels' long fight for communist rule in these states.
Maoist aims
The Maoists' military leader is Koteshwar Rao, otherwise known as Kishenji.
Thousands of rebels are said to swell his guerrilla ranks - estimates vary from 10,000 to 20,000 armed fighters. They are said to get most of their weapons by raiding police bases.
Analysts say the longevity of the Maoist rebellion is partly due to the local support they receive.
The rebels say they are fighting for the rights of indigenous tribespeople and the rural poor who they say have been neglected by governments for decades.
Maoists claim to represent local concerns over land ownership and equitable distribution of resources.
Ultimately they say they want to establish a "communist society" by overthrowing India's "semi-colonial, semi-feudal" form of rule through armed struggle.
Maoist Rebels Profile
