New Delhi:An ordinary flour mill grinder became a key tool for thearrested doctorfrom Pulwama to turn chemical substances into explosives, possibly similar to those used in the deadly car blast nearRed Fortthat killed 15 people and injured several others. The National Investigating Agency (NIA) investigating the case found the explosive-making setup at the house of a taxi driver in Faridabad. The Pulwama doctor, who played a major role in the Delhi blast case, apart from the Al-Falah assistant professor, had rented a room there and stored a flour mill, a grinder, and other electronic machines. According to investigators, he used this rented space to prepare explosives by grinding urea and separating ammonium nitrate from it to refine the material, and had been doing this for a long time. It was from this same room that police recovered 360 kg of ammonium nitrate and other explosive substances on November 9 - a day before the deadly car blast in Delhi on November 10. Also read-Delhi Doctors with Foreign degrees under investigation in terror probe During the interrogation, the doctor, who was also associated with Al-Falah University, confessed to the investigators that he first took the flour mill, the grinder, and other electronic machines to the driver's home, saying that they were gifts for his sister's wedding, and later, shifted them to his rented accommodation. Following the confession, the investigators detained the taxi driver for questioning. The driver told the NIA, as reported byNDTV,that he met the doctor when he had taken his son for treatment at the Al-Falah Medical College and Hospital about four years ago. had reported that two doctors, both from Pulwama, were arrested in Faridabad after police discovered 2,900 kg of IED-making material from two houses they had rented. The haul included ammonium nitrate, chemicals, wires, batteries, and remote-control devices, all ingredients for large-scale explosions. Foreign Handler Sent 42 Bomb-Making Videos to Al Falah Doctor In the latest development in the case, the investigating agency found that one of the three alleged foreign handlers linked to the accused doctors from Faridabad’s Al Falah Medical College reportedly sent 42 bomb-making videos via encrypted apps to one of the arrested doctors, who had rented a place that housed a flour mill and stored explosives. According to the NIA team, the three suspected handlers in the case are “Hanzullah,” “Nisar,” and “Ukasa”, which are also believed to be pseudonyms. Investigators told theIndian Expressthat the videos were shared through encrypted messaging apps by a handler using the name "Hanzullah", whose identity the investigators believe is likely a pseudonym. This handler is said to have directly sent the videos to the accused doctor, who prepared the explosives in his rented room. The roles and identities of the handlers, who investigators believe helped the module build a bomb and nudged them on the path of a suicide attack, are now being scrutinised by security agencies for overlaps with incidents involving a similar modus operandi of do-it-yourself (DIY) bombings in India in recent times, said Indian Express sources in Karnataka familiar with the Delhi probe. Also read-How doctors interrogation led to unraveling of major terror plot