Tribespeople in parts of West Bengal support the rebels
Friday's train crash in India has been blamed on "sabotage" by Maoist rebels. It was the latest in a series of rebel attacks after the government launched an offensive against them. The BBC's Soutik Biswas asks whether the rebels are gaining the upper hand.
It is not surprising that Maoist rebels are being blamed for the derailment of an express train in India's West Bengal state, in which 148 passengers were killed.
The police claim they have found posters signed by a local Maoist militia claiming responsibility for removing part of the track, which led to the train skidding off and colliding with a freight train coming in the opposite direction.
West Midnapore district, where the incident happened, is the hotbed of Maoist rebellion in West Bengal, one of the states where the rebels have a presence.
Tribespeople dominate the district, especially the forested Junglemahal region bordering Jharkhand state.
They feel ignored and deprived by the Communist government which has been ruling the state since 1977. Most live in abject poverty. The only visible signs of "development" I spotted during a trip to the area some years ago were cheap liquor shops.
Fed up with the state of affairs, Junglemahal's tribespeople even agitated for a separate state.
When neighbouring Jharkhand was carved out as a separate state, their alienation grew and they were quick to welcome the Maoists, who wield most influence in areas which are poor and dominated by tribespeople.
The security forces are on the backfoot after a spree of rebel attacks
The Lalgarh area in Junglemahal is the rebels' most formidable stronghold.
In February, they stormed a police camp in Lalgarh, killing 24 policemen.
Rebels love to describe Lalgarh as a "liberated zone" where the state has withered away - schools and medical centres have closed down because teachers and doctors are afraid to attend, and policemen are confined to the police stations fearing reprisals.
Friday's incident in West Midnapore demonstrates how the rebels are taking the battle to their enemies ever since the federal government launched an offensive in what is known as India's "red corridor" earlier this year.
This comprises 223 of India's 636 districts in 20 states which the government says are "Maoist affected", up from 55 districts in nine states six years ago.
Ninety of these affected districts, the government says, are experiencing "consistent violence."
The rebels have been carrying out attacks with impunity in recent months - two major attacks Dantewada in Chhattisgarh state left more than 100 people dead, including 75 paramilitary troops.
But there are also theories that in this case the Maoist script went slightly awry.
Maoists frequently tamper with railway lines and often these lead to minor derailments; a number of such attempts have been caught well in time. There have been hijackings but no major attacks on civilian transport with such a death toll.
In the past year, Maoists have carried out 32 attacks on railways, mainly in Jharkhand, West Bengal, Orissa, Chhattisgarh - but no major casualties have been reported.
Support for the Maoist cause across India generally will be dented by such an attack, just as it was after the assault on troops in Dantewada.
Following the twin Dantewada attacks, the government said it was reviewing its strategy for fighting the rebels, who have refused to respond to repeated government offers for talks.
Analysts say that the strategy of "clearing, holding and developing" rebel-affected areas evidently inspired by the US strategy in Iraq and Afghanistan is not working.
One reason, they say, is that the surge of security forces and resources on the ground are not sufficient enough to take on the rebels who are spread over a vast swathe of remote mineral-rich forest lands.
Maoists call Lalgarh a "liberated zone"
The government is now in a "visible retreat" after a spree of rebel attacks, says security analyst Ajai Sahni.
He believes that a lack of adequate forces, training and intelligence is leading to these "disasters".
"Unless local capacities for intelligence and operations are enormously augmented, this [offensive] can go nowhere, and lot of lives are going to be lost for no useful purpose," Mr Sahni says.
But the under-equipped local police and intelligence-gathering networks remain Indian security' s weakest link, and there no visible efforts to bolster them.
The government appears to be confused over how the rebels should be tackled - there are differences in the ruling Congress party itself on whether the state should strike hard against it's own people.
Recently federal home minister P Chidambaram requested wider powers to deal with the rebels, saying that he had been given a "limited mandate."
He said the chief ministers of some of the worst affected states have asked for air power to be used against the rebels - a measure that the government has refused to sanction.
Analysts believe that many states are not doing enough to take on the rebels, leading to a "centralisation" of the problem.
The train '"sabotage" was one of the biggest attacks launched by the rebels
"The principal responsibility for dealing with the Maoists remain that of the states; the first responders, the local police stations, have to be strengthened and equipped to deal with the task on their own," says Ajai Sahni.
Till that happens, the rebels will be seen to have an upper hand in what promises to be long drawn out and bloody conflict, the like of which India has never seen.