India’s Maoist insurgency – its biggest internal security challenge, according to former prime minister Manmohan Singh – has grown in the past few years. A guerrilla attack killing 76 police in Chhattisgarh state in April 2010 was the worst in the ‘Naxalite’ rebellion’s 43 years. Today’s movement harks back to a peasant uprising in the West Bengal village of Naxalbari. However, violence has surged since 2004, when the People's War Group and the Maoist Communist Centre merged into the latest left-wing grouping, the Communist Party of India–Maoist. The rebels say they are fighting to protect the rural poor against the 'social oppression' of the caste system and 'eco-imperialist exploitation' by multinational mining firms in resource-rich regions. Many recruits are tribal people, but many leaders educated urbanites. The number of Naxalites is unknown – estimates range from 14,000 to 120,000 – but they cut a large ‘red corridor’ across central and eastern India. Despite recent attempts at coordination by New Delhi, the insurgency has traditionally fallen under the law-and-order remit of state governments. But some of the worst-affected states, such as Chhattisgarh and Jharkhand, are India’s poorest, incapable of addressing the terrorist threat or the social inequality at its root.