New Delhi, July 15 - The central and state governments have been tardy in tackling the Maoists, Home Minister P. Chidambaram said Wednesday, three days after 29 policemen were killed in Chhattisgarh.

'Regrettably, we did not challenge the threat of Leftwing extremism adequately. Today, this poses a grave challenge,' the minister said in the Rajya Sabha during question hour.

Chidambaram added: 'We are preparing to take on this challenge but the details cannot be disclosed.'

He said he had visited the Maoist-affected states. The government planned to hold a meeting in August to discuss a roadmap to take on the Maoists.

'We now have a military advisor to help us draw up our plans.'

Chidambaram's comments came after Maoist guerrillas gunned down 29 policemen Sunday in Chhattiagarh's Rajnandgaon district in one of the most horrific massacres blamed on the rebels.

Thousands have been killed in violence linked to the Maoist insurgency in India that began in 1967 and shows no signs of ending.

Chidambaram underlined that he did not favour non-state players taking on the Maoists. This work was best left to authorities of the areas where the cancer existed.

The comments were clearly aimed at the Chhattisgarh government whose state-funded, anti-Maoist Salwa Judum militia has been widely criticized for rights violations.