Preliminary forensic findings have confirmed what investigators feared, the high-intensity explosion that ripped through a white Hyundai i20 near the Red Fort on November 10 was driven by Ammonium-Nitrate Fuel-Oil (ANFO) combined with detonators a lethal pairing that turned an ordinary vehicle into a walking bomb and left nine dead and more than twenty injured in one of Delhi’s worst urban blasts in recent memory.
Sources involved in the probe say traces of ammonium-nitrate (NH₄NO₃) and fuel-oil residues recovered from the blast site match the signature of ANFO a bulk industrial explosive notorious for its destructive power, availability and the ease with which it can be made into an improvised explosive device (IED). Investigators are treating the explosion as a premeditated, high-impact attack that used established tradecraft: procurement of raw materials, assembly of an insensitive but powerful charge, and the use of a detonator or booster to set off the main load.
Ammonium-nitrate by itself is a white crystalline fertiliser widely used in agriculture and mining. Chemically stable and non-explosive in normal handling, it becomes a potent oxidiser when wetted with fuel oil typically a mixture of about 94 per cent ammonium-nitrate and 6 per cent fuel oil. In this configuration (ANFO), the compound is relatively insensitive to casual ignition meaning it can be transported and stored without easy accidental detonation but requires a high-energy stimulus such as a detonator or booster to initiate a supersonic shock wave.
That shock wave is what makes ANFO devastating: the rapid chemical reaction produces enormous volumes of hot gases in microseconds, generating a pressure front capable of shredding metal, collapsing structures and producing deadly shrapnel. Even with a comparatively moderate detonation velocity (roughly 3,200 m/s), the sheer mass of ANFO in a confined space such as the trunk or rear section of a vehicle can create a catastrophic fireball and pressure wave, exactly as seen at the Red Fort stretch.
Forensic teams at the site recovered prilled ammonium-nitrate particles, fuel-soaked residues and detonator fragments, pointing to a planned, professionally executed device rather than an accidental or low-grade incendiary.
ANFO is not a new weapon; it is the standard bulk explosive used in open-pit mining and quarrying. In legitimate industry practice, it is prepared on site and used immediately in boreholes there is usually no routine packaging, long-term storage or transport of the mixed ANFO. Regulatory frameworks exist precisely to distinguish industrial use from potential misuse: India classifies mixtures with more than 45 per cent ammonium-nitrate as explosives, and possession of blasting accessories such as detonators requires licences and returns to authorities like the Petroleum & Explosives Safety Organisation (PESO) and district officials.
Yet history and recent probes show that the attributes that make ANFO practical for mining low cost, ease of mixing, and bulk lethality also make it attractive to terrorists. Investigators told media that the Red Fort device bore hallmarks of an explosives cache converted for malicious purposes: pre-mixing or staged mixing of prilled ammonium-nitrate with fuel oil, insertion of a detonator/booster, and concealment within a vehicle to maximise casualty impact in a dense urban pocket.
Officials also flagged the technical challenge attackers face with ANFO: its insensitivity. To overcome that and produce a reliable detonation, perpetrators must employ booster charges and reliable detonators, the very items tightly regulated under Explosive Rules, 2008. The presence of detonator fragments at the Red Fort scene underscores a deliberate plan to overcome ANFO’s safety margin and to ensure the device would detonate exactly when intended.
India’s regulatory history with ANFO has been complex. While ANFO manufacture and on-site use in mines and quarries historically required industrial permissions and returns, policy shifts sought to ease the compliance burden for legitimate industry users. Notably, a 2014 Department of Industrial Policy & Promotion (DIPP) decision abolished certain licensing requirements for ANFO preparation by mine owners an administrative move intended to facilitate mining and construction activities and avoid operational bottlenecks. The government nonetheless retained strict controls over blasting accessories boosters, detonators and safety fuses which continue to fall under explosive rules and require No Objection Certificates (NOCs) and returns to authorities such as the DGMS and PESO.
Security analysts warn that regulatory leniency for industrial ANFO use, if not matched by iron-clad tracking of detonators and accessories, creates opportunities for diversion. The Red Fort blast appears to exploit precisely that gap: commercially available oxidiser (ammonium-nitrate) combined with illicitly obtained detonators can produce an IED with mass casualty potential.
Beyond the chemistry, the human elements are equally damning. Investigators say a Hyundai i20 the vehicle that exploded was used as the container and delivery mechanism for the ANFO charge. Authorities recovered detonator fragments and AN traces consistent with a pre-placed or vehicle-borne device. Early leads also point to a possible link with a terror module recently uncovered in Faridabad, where explosive material and accessories were seized in operations that predate the Red Fort blast by hours. One name now under the scanner is Dr Mohammad Umar, who is alleged to have been alone in the car when it detonated and whose suspected links to regional terror networks remain under intensive investigation.
Whether the device was remotely triggered, timer-activated, or manually detonated remains a focus of forensic analysis. The presence of detonators means the attackers had both the intent and the technical means to convert a stable industrial compound into an instrument of mass death.
