Those involved in the Hyderabad twin blasts will be brought to book and no stone will be left unturned, Additional Commissioner of Police (city crime squad) Punna Rao said on Tuesday.

Rao, who is supervising the investigations, told rediff.com that the police was looking into every possible angle and added that he was sure that the case will be cracked.

When asked about the fake currency angle into the Hyderabad blasts, he said, "It's not that we are not looking into that angle. It is too premature to draw any conclusions, but no stone will be left unturned."

Hyderabad Police had recently cracked a huge fake currency racket. Reports said suspects in this racket were present at the blast spot and that two of them had suffered injuries.

Talking tough, Rao said terrorists will not be 'successful in bogging the city down.'

"Hyderabad is still a safe city and there is nothing for people to worry," he asserted.

The use of Neogel-90 in the blasts had initially foxed investigating agencies. Neogel-90, a substitute for gelatin sticks, is used by miners. In the past, attacks using Neogel-90 were carried out only by Naxals.

According to Rao, Neogel is easily available in the open market but is sold only to licensed users. He did not rule out the possibility of any person with a valid license having supplied Neogel to the terrorists.

He also added that the person who carried out the blasts could have also obtained a fake license and purchased Neogel. Rao said this angle too was being probed.

Rao refused to divulge more information on the investigation, stating that it will be counter productive to the case.

Handy cam:

The police seem to be sure that the culprit could have been at the spot and may have also been injured. The officer said any on the spot visuals would help the investigation a great deal.

The Additional Commissioner said that at Lumbini Park, there were at least 590 tourists on the day of the blasts. He said requests had been sent out to persons carrying handy cams.

"Information on a person carrying a black bag at the venue is also being sought for," he said.