Indian Maoist rebels, active across half the country and apparently able to strike at will, are a potent symbol of how the fruits of an economic boom have not been enjoyed by all.
In recent years, they have ambushed police and military posts to steal weapons or kill security forces, taken over public buildings and in their latest attacks on Wednesday taken over a train along with hundreds of hostages.
The rebels say they are fighting for the rights of the poorest of the poor, and say their ultimate goal is to capture India's cities and overthrow parliament.
Based in the dense forests of the eastern state of Chhattisgarh, the ultra-leftist rebels have found a fertile recruiting ground among rural tribal villagers and landless farmers.
Life in India's hinterland for most is far removed from the millions of dollars being made there from the mining and export of minerals.
The most common work is subsistence farming, and the gathering and selling of leaves for Indian "beedi" cigarettes a job that brings in a meagre 35 cents a day, the lowest level of any state in the country.
Such contradictions of modern India are being played up by the Maoists now believed to be spreading operations across the east and even in states around the capital New Delhi.
The insurgency, which grew out of a peasant uprising in 1967, has spread to 15 of India's 29 states from just four in 1996.
Estimates of the rebel army size nationwide range between 10,000 and 20,000, but little is known about their shadowy leadership -- which does not court the media and seldom issues statements.
The common denominator of each attack is the apparent ease and confidence with which the rebels operate.
Indian Prime Minister Manmohan Singh in 2006 described the Maoists known in India as 'Naxalites' , as a "virus" and ranked them along with Islamic militants as a serious threat to the country's internal security.
But while the pool for converts to the Muslim insurgency in Kashmir is limited, the Maoists could potentially attract tens of millions of poor.
With India's security forces struggling to contain the problem, and no sign of India's boom filtering down to the lowest echelons of society despite promises of rural development, India's Maoist insurgency can only be expected to worsen.
"We are seeing a process of very systematic extremist mobilisation which will translate into violence over the next five to 10 years," said Ajai Sahni, executive director of the New Delhi-based Institute for Conflict Management.
"You are talking about 10 percent (economic) growth, where 77 percent of the Indian population that is 836 million, is living on less than 20 rupees a day, which is 50 cents. The Maoists understand the contradiction."