Acknowledging that "something went wrong" in the worst-ever Maoist attack in Chhattisgarh, Government on Thursday decided to set up an inquiry into the incident that claimed lives of 76 security personnel.

"We have taken a decision to institute an inquiry into what went wrong," Home Minister P Chidambaram told reporters on a volley of questions on Tuesday's attack in the jungles of Dantewada district in Chattisgarh.

Noting that there would be a time-frame for the inquiry, he said, "I maintain what I said yesterday that something went wrong. We have to find that out."

Chidambaram was briefing reporters after a meeting of the Cabinet Committee on Security, but refused to divulge what was discussed there.

Asked whether the Maoist attack figured in the meeting of the Union Cabinet held earlier in the day, he merely said "no".

Chidambaram described as incorrect reports about pressure bombs being used in the attack and also that the state police did not know about the CRPF operation for area domination.

He said 76 security personnel, including a driver of a mine-protected vehicle and a head constable of the state police, were killed in the landmine blast.

Asked about the source of weapons used by the ultras, Chidambaram said the extremists had taken away all arms of the CRPF personnel after they were killed in the attack.

"They buy arms from across the border. There are arms bazars across the border. They bring them clandestinely into the country," he said, citing India's open and porous borders with Nepal, Myanmar and Bangladesh.

"Where do the Northeast insurgents get their arms from? Arms are looted from security forces, procured from across the border, country-made weapons are acquired".

To questions on the sources of funds, he said they loot banks and extort money from mining companies in the areas where they operate.

Asked about the use of airpower, Chidambaram refused to elaborate on Prime Minister Manmohan Singh's comments that Government had not taken any decision to use airpower to quell extremist violence.

"My view is that if necessary, we can revisit it. We have to reflect on it," he said, adding "if there is a policy revision, you will be informed".

Asked whether the shortage of mine-protected vehicles (MPVs) would affect the anti-naxal operations, the Minister said "that is a decision the operational commanders have to take. In some places, they may review (the operations), in others they may go ahead and intensify."

"We will provide paramilitary forces to the state governments to assist them to carry out anti-naxal operations, regain control so that they can restore the developmental process.

"So, therefore, whether the operations will continue or intensify, these decisions have to be taken by the state government and the operational commanders," he said.

Chidambaram said a large number of MPVs have been ordered by the paramilitary forces, including 280 by the CRPF. This was due to the "extremely limited capacity" of the Indian public and private sectors to produce them.

He said an MPV was blown up in the Tuesday's landmine explosion by the naxals as it was "designed to take a blast of 15-20 kgs. But if you have a larger charge, then it will be damaged." The driver of this MPV was killed.