Scores of Indian soldiers killed in Maoist ambushes
Families perform funeral rites for victims as officials condemn the attack
Maoist rebels have killed at least 75 Indian soldiers in a series of attacks on security convoys in the central state of Chhattisgarh, officials say.
A large patrol of federal paramilitary troops was ambushed at dawn by hundreds of heavily armed insurgents in a remote part of Dantewada district.
Rescue teams were later ambushed in attacks using landmines and gunfire.
Correspondents say it is the worst attack on security forces by the rebels since their insurgency began.
By Soutik Biswas BBC News, Delhi
The attack on troops in Chhattisgarh is the deadliest since the insurgency began in the late 1960s - and a major setback for the government's latest anti-Maoist operation.
Although details of the attack are still sketchy, it is clear it will not be easy for security forces to defeat the rebels in their strongholds - vast swathes of remote mineral-rich jungles home to tribespeople who form the main support base for the rebels.
Questions have been asked about levels of intelligence and whether security forces are trained to operate in such hostile terrain.
The attack is also a blow to the government - it comes days after Home Minister P Chidambaram described the rebels as "cowards enacting dramas". With the prospect of dialogue unlikely, it appears the government is in for a long and difficult war.
India's Home Affairs Minister P Chidambaram said the attack showed the brutality and savagery that the rebel army was capable of.
But he suggested lessons had to be learnt quickly by the security forces.
"Something has gone very wrong. They seem to have walked into a trap set by the Naxalites [Maoists]. Casualties are quite high and I am deeply shocked," he said.
Home Secretary Gopal K Pillai said that the rebels had booby-trapped the area of the ambush.
"Preliminary reports indicate that the Maoists planted pressure bombs in surrounding areas at places where the security forces might take cover," he said.
"As a result of this, the bulk of the casualties have arisen from the pressure bomb blasts."
The Maoists have stepped up attacks in recent weeks in response to a big government offensive along what is known as the "red corridor", a broad swathe of territory in rural eastern and central India where the Maoist rebellion has been gathering strength.
Nearly 50,000 federal paramilitary troops and tens of thousands of policemen are taking part in the operation in several states.
The rebels have tapped into rural and tribal anger among those who have seen no benefits from India's economic development and this attack is another chilling reminder of the growing threat they pose, says the BBC's Chris Morris in Delhi.
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