Two days after the blast at Mecca Masjid in the Old City area which has claimed 16 lives so far, investigating officials are scanning over one lakh calls routed through a Hutch tower in the vicinity of the mosque on Friday afternoon. They hope to find a link to the Hutch SIM card in the cellphone detonator of the defused second bomb.

“It is a huge process of eliminating calls routed through the tower from 1-1.30 pm on Friday afternoon. It can lead to the number that was attempting to trigger the second blast or even people monitoring the operations,” said an official.

Sources said details of all calls and SMSs made to and from the recovered SIM card have been obtained from the service provider. The data is being analysed. However, it is still not clear if the failed bomb was to be triggered by a remote phone call or through an inbuilt alarm clock in the cellphone.

“The information lies in the electronic circuit of the phone which was damaged when the bomb was defused. We have to reconstruct it to provide a clear answer,” said explosives experts.

Officials are not ruling out the possibility that fake SIM cards may have been used too. The police are also tracking the International Mobile Equipment Identity (IMEI) numbers of the two Nokia handsets used in the bombs. Using the IMEI number, officials have found that one phone was bought in West Bengal.

The IMEI number (35393801248899) of the cellphone used to explode the first bomb has also been salvaged. The details of the SIM card destroyed in the blast have been obtained through this number.

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