Ruling out any security lapses in the arrangements for BJP Prime Ministerial candidate Narendra Modi's mammoth 'Hunkar' (battle cry) rally, Nitish also said there were no intelligence inputs about the explosions either from the Centre or from the state.
The serial blasts cannot be a coincidence that they occurred on the day of the rally, he asserted.
"Whatever happened is not the tradition of Bihar. An attempt was made to disrupt the amity of the state and disturb the law and order situation. The blasts before the BJP rally seems like a deliberate attempt," he told reporters.
"The day and timing of the serial blasts indicate that there was an attempt to vitiate the atmosphere in the state. The timing is very worrying," he said.
Asked if the blasts could be the handiwork of some terrorist outfits, Nitish, who was flanked by DGP Abhyanand and Chief Secretary A K Sinha, did not rule it out.
Appealing for peace, Nitish said, "Some elements are trying to create trouble. We have to face (them) unitedly."
There were no security lapses as all the necessary measures had been taken for the BJP rally, he added.
Defending the arrangements, Nitish said "There were no intelligence inputs either from the Centre or from the state. Whatever was possible to do for this kind of a programme, the administration had done.
"I would like to assure BJP that there were no shortcomings in the arrangements," he added.
But, despite the arrangements, blasts had taken place, he said.
"It was a lesson for us as, despite the bandobast, this happened. It is a matter of great concern for all of us and a challenge for the entire state," he said.
The security agencies will surely track the people behind these blasts and the conspiracy will be exposed, he added.
Noting there have been political rivalries but no history of confrontation at events, Nitish said even though parties oppose each other in political ideology, there is a need to remain united to fight these mischievous elements.
"We may be political rivals, but can never allow such an unpleasant event to happen at a political rally."
Kumar announced ex-gratia payment of Rs 5 lakh each for the next of kin of those dead. Three of the deceased have been identified.
He said based on information gathered by Principal Secretary Health Deepak Kumar, of 83 injured who had come to Patna Medical College and Hospital, 38 were under treatment and the rest discharged.
The Chief Minister said the condition of two persons including the man who was injured in the first explosion in a toilet at platform number 10 at the Patna railway station was critical.
He said one person who was running away from the railway station after the explosion was caught and some vital documents were seized from him.
Kumar said he had talks with Prime Minister Manmohan Singh, Home Minister Sushilkumar Shinde and BJP patriarch L K Advani after the explosions.
Describing the blasts as a blot, he said the perpetrators would be dealt with.
Stating that the bombs which exploded were of low intensity, DGP Abhyanand said that seven blasts took place between 9:30 AM and 11:45 AM in which timers were also used. Four bombs were recovered near the Gandhi Maidan and defused. Another two unexploded bombs each were recovered near Gandhi's statue and two towers and defused, he said.
The Chief Minister, who cancelled a visit to Munger to attend an international conference of yoga, said he would attend the JD(U) convention at Rajgir starting tomorrow.