A day after it was excluded from all the action as far as investigations into the Delhi high court blast are concerned, the special cell of the Delhi Police has been asked to increase its strength, sources said.
During a brief meeting at the ministry of home affairs on Thursday morning, an eight-member team of the special cell is understood to have told officials that the blast bore the imprint of the Indian Mujahideen (IM) and was executed using large quantities of ammonium nitrate and potassium chlorate.
The home ministry told the special cell to induct an additional 1,000 officers to its ranks and resurrect its grassroots-level intelligence gathering mechanism by taking in young blood.
"The additional requirement will be filled in by drawing officers with certain basic skills and experience ranging from 10 to 15 years," said a senior police officer. Even as PN Aggarwal, special commissioner of the special cell, met a small contingent of officers from the National Investigation Agency (NIA) at the cell's New Delhi office in Lodhi Colony on Thursday afternoon, NIA chief SC Sinha sought inputs from commissioner of Delhi Police BK Gupta.
The police said more than 250 phone numbers were under surveillance and a chunk of calls, both incoming and outgoing and made to or from Bangladesh, Pakistan and Nepal were being analysed.
Though they are yet to get their hands on a battery, which was probably used while assembling the improvised explosive device on Wednesday afternoon, sources said that four persons including a complainant related to a cheating case, which had the police on their toes as they looked for a stolen Santro car, have been detained for questioning.