More than 1,000 Maoist fighters, armed with sophisticated weapons, ambushed 81 central police in a forested area of insurgency-hit central Chhattisgarh state on Tuesday, exposing a lack of intelligence and planning.

Since the attack, the government has come under criticism from opposition parties who say it has failed to tackle the insurgency. Pressure to do more could rise as India faces polls over the next two years in eight key states, including some Maoist-hit ones.

“I accept full responsibility for what happened in Dantewada (in Chhattisgarh),” Palaniappan Chidambaram said on Friday at a New Delhi ceremony to mark the deaths.

“I have been asked directly and indirectly, where the buck stops for what happened,” said Chidambaram, who was named home minister after the 2008 Mumbai attacks to plug gaps in the security system. “I have no hesitation in saying the buck stops at my desk.”

Indian newspapers have carried front-page stories on the government’s failure to tackle the decades-old insurgency that began with a peasant’s movement in 1967 in the eastern state of West Bengal and has now spread to 22 out of 28 states. “No water, food or medicines. Now, go fight ‘biggest threat’,” The Times of India newspaper said, highlighting the challenges in training and equipping the police force. The police killed in Tuesday’s ambush were not trained in jungle warfare before deployment in the Maoist stronghold in Chhattisgarh, officials said after a preliminary investigation.

Thousands of paramilitary troops have been scouring the jungles in east and central India, officials said. The government says it will consider use of the air force to aid police in future offensives against the rebels, but has so far ruled out using the army. India has hesitated to use the army to tackle counter-insurgency, experts say, because of sharp criticism after pressing it to root out a Sikh insurgency in 1984 in Punjab state.

The Maoists snatched weapons including light machineguns and mortars in this week’s surprise attack, and lost eight men, a rebel commander said in a statement to local media on Friday.

Besides raiding police bases for weapons, the rebels also buy them from Chinese smugglers and are in touch with other militant groups operating in India, including Kashmir and the northeast.

The estimated 20,000 Maoist combatants operate across a “red corridor” stretching from the Nepal border to West Bengal and through central India into the southern state of Andhra Pradesh.