The governments of the husband (Prasad) and wife (Rabri Devi) had ruined Bihar during their rule between 1990 and 2005, he told a public meeting here.
Taking on the RJD supremo for questioning lack of development in Bihar, Kumar said the NDA government built the roads on which Prasad was travelling to take out his 'Parivartan yatra'.
Denouncing the violence during his 'Adhikar Yatra' by protesters, including contractual teachers, Kumar said there was no place for violence and arson in democracy.
"Everybody has a right to protest in a peaceful manner and criticize others by exercising one's fundamental rights under the Constitution ... But if the criticism takes the shape of violence and abuse then it is a matter of grave concern," he said.
Kumar also hit out at BJP MP from Purnia, Uday Singh for staging 'Vedna rally' in his constituency last week.
It has become fashionable to criticise him but it hardly made any difference to him, Kumar said adding he had pledged to get the special category status for Bihar and would not deviate from it.
He urged the Centre to adopt a flexible approach to consider the demand for special status to Bihar in view of the backwardness of the state.
Meanwhile, elaborate security arrangements were made in Purnia district for Kumar's visit and people carrying black cloth were strictly prevented from reaching the meeting venue, official sources said.
