Police say Improvised Explosive Devices or IEDs were used in the blasts. Two special teams set up by the Andhra Pradesh government are assisting the National Investigation Agency, which has taken over the probe. Eyewitnesses are being questioned and sketches of suspects being prepared.
Home Minister Sushil Kumar Shinde visited the blast sites today and reiterated that an intelligence alert received two days ago was not specific to Hyderabad. He said the families of the dead will be given a compensation of Rs. 6 lakh by the Andhra Pradesh government and Rs 2 lakh by the Prime Minister.
Mr Shinde will make a statement on the blasts in Parliament today. The opposition BJP has moved for suspension of Question Hour in the Rajya Sabha for a discussion. BJP chief Rajnath Singh is visiting Hyderabad today.
The bombs, placed on bicycles near a small restaurant in Dilsukhnagar, went off just after 7 pm yesterday, within five minutes of each other. The Hyderabad police chief, on way to the Sai Baba temple, had passed by about 15 minutes ago.
The second of the two bombs was planted on a foot overbridge, where an unexploded bomb was defused during the serial explosions in 2007.
As investigators dig through the remnants at the blast site, there are concerns that crucial forensic evidence may have been destroyed by crowds swarming the area last night. Police baton-charged but failed to disperse them for several hours.
No organisation has claimed responsibility for the terror attack. But the Delhi Police says an alleged member of terror group Indian Mujahideen had admitted to surveying three places in and around Hyderabad, including Dilsukhnagar, in October last year.
Prime Minister Manmohan Singh criticised the bomb blasts as a "dastardly attack" and assured that the "guilty will not go unpunished".
Delhi, Mumbai and other major cities have been put on high alert.
Hyderabad, where twin blasts killed 40 people in 2007, is scheduled to host the second Test match between India and Australia on March 2.