The Gujarat Chief Minister touched on the terror blasts in his Patna rally in October last year on the day of his rally to hit out at Kumar.
"The border (Bihar's) with Nepal is a cause for concern. Bihar has become a haven for terrorists due to vote bank politics of the government. It has not adopted tough policies against them to appease some people," he said.
You may not like Modi or BJP but those who died in the blasts were also from Bihar, he said.
"Those indulging in the politics of vote bank do not understand this ideology... Sooner we get rid of such people, the better it is."
Welcoming Paswan, Modi said that NDA's strength was going to grow further and so would the troubles of his rivals.
"They think that BJP, which (they) thought of as a party of Baniyas and Brahmins, has declared a man from OBC as their PM candidate... Let me tell you, the next decade will belong to SCs, STs, the poor and marginalised," he said.
Ridiculing the fledgling Third Front, of which Kumar's JD(U) is a member, he alleged that the country's development was the least of their concern. Most parties in the front have been Congress allies, he said.