The blasts were set off Friday in Lucknow, capital of northern Uttar Pradesh state, and Faizabad and Varanasi in the same state.
The Press Trust of India reported ix blasts, all in the vicinity of crowded courts, claimed 14 lives, and left at least 50 people injured. Some of the bombs had been planted on bicycles.
A police official in Varanasi said nine of those killed were from his city, one of the holiest cities for Hindus because the sacred Ganges River flows through it.
The blasts reportedly came a week after security agencies in the state foiled an alleged plot and arrested three suspected members of the terrorist group Jaish-e-Mohammed, based in Pakistan. Earlier reports said the three had planned to abduct a prominent political figure, possibly Rahul Gandhi.
State Chief Minister Kumari Mayawati blamed the attacks on the failure of federal intelligence agencies, the BBC reported.