Investigators today claimed to have got "vital clues" in the probe into the twin blasts in the city and were examining CCTV footage with the needle of suspicion zeroing in on banned militant outfit Indian Mujahideen.

Dismissing speculation that the CCTV cameras near the blast site were not functioning, Hyderabad Police Commissioner Anurag Sharma said the video footage was available to them and was being analysed.

The CCTV camera which was at the spot at Dilsukhnagar had been functioning till about 8.30 PM on Thursday.

"The speculation that somebody had cut the wire is not true. We have the footage from that camera, which we are analysing," he told reporters here.

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.

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".

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 ongoing investigation.

The investigation by the state police has been handed over to Special Investigation Team (SIT) headed by Additional Commissioner (Crime) Sandeep Shandilya. Six special teams are also on the job.

The investigators have started gathering material, forensic and other forms of evidence and experts from other agencies have also been roped in, he said.

The police have started examining witnesses on the scene.

He said the explosives used for the blast was ammonium nitrate IEDs created on timers which helped those who carried out the strike to time them precisely.

A high alert has been sounded and the city police has increased police deployment, doubled the bomb detection squads and stepped up surveillance on vulnerable areas.

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.

On February 15, a communication was received from the central government which said besides Hyderabad, Delhi, Mumbai and Bangalore may have some retaliatory attacks.

These were promptly communicated down the line and all precautions were taken, he said.

The commissioner said they were on maximum alert since November last year after some incidents in old city.

The city police have been conducting checking and frisking operation in the entire city regularly, he said adding police along with other agencies like OCTUPUS and counter-Intelligence wings was taking necessary measures.

"There was high alert in the city and bomb disposal squads have been increased from 16 to 30," the commissioner explained.

According to Sharma as many as 265 out of 303 CCTV cameras, most of them installed to monitor traffic movement, have been functioning while 23 were not working.

In Mumbai on a private visit, senior BJP leader L K Advani squarely blamed Pakistan for the Hyderabad blasts accusing it of launching a "proxy war" against India.

"There is no doubt that there is the hand of the neighbouring country in Hyderabad blasts. The neighbouring country has not been successful in waging a war against India in the last few decades, so it has resorted to a proxy war," he told reporters.