Police also announced Rs 10 lakh award for information leading to the perpetrators of Thursday's serial blasts that left 16 dead and 117 injured.
"We have already gathered vital clues in the case. We are confident we will crack the case soon," state Home Minister P. Sabita Indra Reddy said after a high-level review meeting chaired by Chief Minister N. Kiran Kumar Reddy. Amid reports that some CCTV cameras at the blast sites were not functioning, the state home minister said 3500 closed-circuit cameras would be installed at vital locations under Hyderabad and Cyberabad police commissionerates to improve vigil.
The modus operandi adopted by the perpetrators like ammonium nitrate and splinters-laden aluminium containers fitted to bicycles used in the blasts were similar to the attacks carried out by Indian Mujahideen.
Without going into details, Hyderabad Commissioner of Police Anurag Sharma said, "We have some evidence, some clues".
"We have footage from the camera (at the blast site) which we are analysing it," he said while refuting media reports that CCTV wires had been cut by the terrorists before their operation. He, however, admitted that out of 303 CCTVs in the city, 38 were not functioning.
The Police Commissioner said they had received an alert from Delhi on February 15 about possible strikes in Hyderabad and three other cities. "We did not take any warning lightly".
Asked about reports of arrests and detentions, he said, "We have not arrested anyone in this case. We are examining all types of evidences."
Asked about the involvement of IM, he said the investigations were underway. "Unless we complete the process, we cannot jump to any conclusion." He said ammonium nitrate was used in the IEDs which had timers.
Sharma said a high alert has been sounded and number of policemen and bomb detection squads increased particularly in vulnerable areas of the city like crowded markets, malls and cinema halls.
Reddy said 15 special teams of Andhra Pradesh police, each having 10-15 personnel, have been constituted to probe the case and bring the culprits to justice.
Investigators were following some leads from CCTV footages, including of a man seen coming to the blast site on a bicycle with a bag. Mobile call records from the area at the time of the explosions were also being examined.
Director General of National Investigation Agency S.C. Sinha discussed with state police officials the on-going investigation.
Meanwhile, Abdul Wasey Mirza, a 23-year-old unemployed youth who fell victim to terror attack for a second time on Thursday in the Dilsukhnagar blasts, has been questioned by police which clarified he is not being treated as a suspect.
"As part of the investigations we only recorded his statement as a witness along with others," Sharma said.
"Nothing like that," Sharma said when asked whether the police suspected Mirza's involvement in the attack after a media report suggested the fact that he survived both 2007 Mecca Masjid and Dilsukhnagar blasts had aroused suspicion about his possible role in the explosions.
Cyberabad and Hyderabad police have questioned some local youths but made it clear that nobody has been detained so far.
"Media reports that we have detained some persons are totally baseless. We only called some people for questioning, which is a normal investigating procedure," a top police official said.
