Eight explosions in crowded areas of the city claimed at least 80 lives and left around 200 people injured. No terrorist group has yet claimed responsibility for the attacks.
"Evil acts such as these have no justification, and the organizers and perpetrators must face severe punishment," the ministry said on its website.
The motive of the attack remains unclear. Police have not accused specific groups over the blasts, but the terrorists are believed to be Pakistani, Bangladeshi or local Islamists, aiming to fuel tensions between Muslims and Hindus. The bombs went off near Hindu temples.
Indian Junior Home Minister Sriprakash Jaiswal, speaking soon after the blasts, said they were part of a "big conspiracy," and that "some foreign hand" could have been involved.
