Manmohan Singh, the Indian prime minister, says they are the biggest internal threat to his country's security.
The Naxalites, or India's Maoists, are blamed for hundreds of deaths every year in the so-called Red Corridor between India's east and south.
Now the prime minster says the government must take steps to stop the violence.
Al Jazeera's Prerna Suri reports.
Source: Al Jazeera