The investigators are scanning the images recorded on a Closed Circuit Television (CCTV) camera mounted on a traffic signal near the blast site in Dilsukhnagar, police sources said.
A man believed to be in his early thirties was seen reaching the place on a bicycle with a bag hung to its carrier a few minutes before the blasts.
He was seen reaching the area at 6.38 pm, 10 minutes before the blast at Anand Tiffin Centre in front of Konark theatre. The second blast took place at 7.01 pm a few meters away. The bombs at both the places were planted on old bicycles.
The surveillance camera installed in front of Dilsukhnagar bus station captured the image of the suspect. However, as his face is not clearly visible, the police are taking the help of experts.
Though the CCTV camera is focused on the vehicles moving on the main road and not towards the corner where the blast occurred, the image of the suspect on bicycle could prove a vital clue in the investigations, sources said.
The police on Friday announced a suitable reward for anyone providing information about the suspect. Cyberabad Police Commissioner D Tirumala Rao said the identity of the person would be kept a secret. He said the reward could be anywhere between Rs 5 lakh to Rs 20 lakh depending on the investigations.
Meanwhile, the condition of the injured remained critical. The injured are undergoing treatment at seven hospitals including state-run Osmania Hospital.