Addressing the Chief Ministers' Conference on internal security, Manmohan Singh said attacks like the May 25 one -- in which 30 people, including senior Congress leaders Mahendra Karma, were killed and many others injured -- were "setbacks" in the process to tackle the extremist problem.
"The meeting today has been called in the aftermath of the brutal attack on Congress workers in Chhattisgarh. Such violence has no place in our democracy."
He said the government has adopted a two-pronged strategy to tackle the Maoist problem -- "proactive and sustained operations against Maoist extremists and, addressing development and governance issues".
He said the meet could be used to find "some concrete measures to deal with the very grave threat of Naxalism".
"The centre and states need to join hands to tackle this problem," the prime minister said.
“I must point out that the challenge of Naxalism has received our serious attention. We have worked on the development of the Naxal-affected areas. We have been successful to quite an extent," he added.