Investigation agencies are scanning 11 CDs of CCTV footage for clues into the Mumbai serial bombings, Home Secretary R.K. Singh said on Friday.
The scooter on which one of the bombs was planted has also been identified, he added.
"There are about 11 CDs (of CCTV footage) which have to be gone through, so it's a voluminous work. People who are not recognised by local people have to be put through a data base...the suspicious people are being verified," Singh told reporters.
"We also have identified the scooter in which one of the bombs was planted. There are various leads based on our previous databases, various people are being questioned, so investigation is going on," he added.
At least 17 people were killed and 131 injured when three blasts rocked central-to-south Mumbai Wednesday evening. The places where the terror strikes happened were Dadar, Zaveri Bazaar and Opera House.