Indian officials have blamed "terrorist organisations" in Bangladesh and Pakistan for the blasts, charges the two governments have denied.
India's home minister acknowledged on Sunday that the government was virtually powerless to prevent attacks.
|"Only the Indians have this kind |
of some supernatural powers that as soon as some terrorist act takes place they know how it happened and who is responsible"
Tasnim Aslam, Pakistan
foreign ministry spokeswoman
"Our country is so big that even if we have the information that something is planned, we do not know where or when," Shivraj Patil, said.
No one has claimed responsibility for planting the bombs - which went off at a packed restaurant and an amusement park where hundreds of people had gathered for a sound a light show - and no arrests have been made.
"Available information points to the involvement of terrorist organisations based in Bangladesh and Pakistan," YS Rajasekhara Reddy, the chief minister of Andhra Pradesh state, where Hyderabad is located, said after an emergency state cabinet meeting.
Reddy did not name the groups or provide proof, saying "it is not possible to divulge all this information".
Bangladesh condemned Saturday's bombings and rejected the accusations that Bangladeshi groups were involved while Pakistan reacted angrily to Reddy's comments, characterising them as an "irresponsible" knee-jerk Indian reaction.
Tasnim Aslam, a Pakistan foreign ministry spokeswoman, said: "They have been making these allegations and nothing ever came out of those allegations and yet they continue maligning Pakistan."
"Only the Indians have this kind of ... supernatural powers that as soon as some terrorist act takes place they know how it happened and who is responsible," she added.
But Indian media reports, quoting unnamed security officials, said the Bangladesh-based Harkatul Jihad al-Islami group known as Huji was behind the attack.
Arati Jerath, the political editor of Indian newspaper Daily News and Analysis, told Al Jazeera she thought that the police suspected a "Bangladesh militant group which we call Huji".
"The police here suspect that it [Huji] is based in Bangladesh but they have local modules - sleeper modules - all over, particularly in South India and the state of Maharashtra," she said.